Dorsai begins recording his daily log as he moves through the jungle. On his way to check Entrapment Area 2, he becomes aware of the sound of an unidentified space vehicle coming in on an unstable re-entry curve. He hears an explosion in the distance and sees a resulting plume of smoke through the trees which offers him a useful reference point. He starts to search for survivors, but finds only one...
Ace slowly comes round and panics when she realises that she can‘t see anything. Dorsai assures her there’s no need to be frightened and promises to answer all her questions if she stops struggling. He tells her she’s wearing a regen mask, and although she’s bound to find it claustrophobic, she can’t take if off yet as she was badly scorched in the accident. In fact, 20% of her body was burned and he had to remove her clothes to treat her, but there’s no need for her to be shy as he’s seen a naked human before. He examines her closely and tells her that the new tissue is firming up nicely, so she can take the mask off tomorrow. The last thing she can remember is being with the Professor in a marketplace on Markeb IV, so she’s surprised to learn that she was on board a ship that crashed. She recalls that the Professor wanted to go to Markeb to get some crystals, but some creep in the market tried to chat her up. She felt something cold and metallic on her neck and realises now that she must have been drugged. The next thing she remembers is waking up here. Dorsai tells her she’s on Yentob Minor, a jungle moon of the Brig System. He hadn’t intended to tell her until she was stronger, but he found twenty bodies of various species inside the wreckage; she was the only human, and the only survivor. From the description she’s given, however, he doesn’t think the Professor was among them. She’s determined to contact her friend, but Dorsai says this is impossible as he doesn’t have a communicator and the one on the ship was damaged beyond repair. She’s shocked when he tells her she’s been unconscious for two days, and she tries to get up, then cries out in agony. He administers a mild painkiller and explains that she had a mild concussion when he found her. The painkiller starts to take effect, and he tells her to get some sleep.
Later, Dorsai collects some fresh flowers and takes them to Dr Cusack and his wife. As he tidies up, he tells them they have a visitor, a young woman with an unusual name. He finds her beautiful -- although after so long he’d probably find any face beautiful -- and he thought he‘d never experience such things again. Night is starting to fall, so he bids them goodnight.
Ace wakes up and just for a moment she thinks everything must have been a dream. She struggles to remove the regen mask, but she can’t work out how to operate the device, so instead she wraps herself in a blanket and starts to feel her way around the room, trying to avoid bumping into anything. The floor and walls are metal, but she finds a chair made of wood. She can’t find a window, but she opens a door and can feel carpet on the other side. She assumes Dorsai is asleep and jumps with a start when a cold robotic voice suddenly asks if it can help her. The voice belongs to the house computer and when she tells it she can’t see, it switches the lights on. That obviously doesn’t help, so it starts to give her directions to the main entrance.
Outside, Ace is grabbed by Dorsai, who warns her that she was heading straight for an electro-magnetic barrier that keeps the animals out of the compound. To prove his point, he asks her to stretch out her hand slowly, and she gets an electric shock. If she’d run into that, she might have been injured or even killed. He orders her back to bed and when she refuses to co-operate and starts struggling, he gives her an injection which puts her to sleep.
The next morning, Dorsai wakes Ace up with breakfast in bed. He notices that she’s not speaking to him, so he explains that he had to anaesthetise her for her own safety. She accuses him of assaulting her, but he promises he would never hurt her. She also refuses to eat anything as she thinks the food could be drugged. She doesn’t trust Dorsai, and convinces herself that she’s being held prisoner on Markeb and that the Professor will be out there somewhere looking for her. Dorsai reminds her she can take her regen mask off today if she wants and she tries to rip it off herself, but fails. Reluctantly she agrees to let Dorsai remove it for her -- but when he does she discovers she still can’t see. To her horror, Dorsai reveals that he knew all along that she’d been blinded in the crash! Ace breaks down in tears and asks Dorsai how he could calmly tell her that as if it meant nothing. He points out that he didn’t say her condition was permanent. He offers to examine her again, but she refuses, believing he may have done this deliberately to keep her here. Although he gives his word that she‘s not a prisoner, she becomes distraught and starts throwing objects across the room, so Dorsai leaves.
On the fifth day since Ace’s arrival, Dorsai notes that she continues to remain isolated in her room and is refusing to eat or let him examine her. Eventually Ace’s hunger becomes too much for her and she realises she’s doing herself no favours sitting alone and being miserable. She forces herself to be positive and asks Dorsai for some clothes, which he orders from the computer. Unfortunately, it’s only programmed to produce standard fatigues, so she asks it to put her name in big swirly lettering on the back. Ace sits to eat and is irritated by Dorsai standing watch over her. She asks him to take her back to the crash site so he can prove he’s been telling the truth, but before they venture outside he wants to put a sterile dressing on her eyes.
As soon as she’s outside the force field, Ace considers making a run for it, but she suspects Dorsai will be even more on his guard than usual. In any case, she’s likely to end up head first in a bog. They make their way through the jungle and Ace is alarmed when he tells her they still have another two hours to go. He offers to carry her, but she rejects the idea outright. They eventually arrive at the crash site, which Dorsai describes as a cargo carrier vessel. Ace realises he could have taken her to any old wreck, so he takes her inside the ship through a hull breach. She’s relieved to get a break from the heat outside, but she can feel soot on the walls, and the smell of burnt flesh is overwhelming. Dorsai quotes a passage from Poe and for a moment, Ace is reminded of the Professor. Nothing in the ship is familiar to Ace until she comes across some deck plates with a raised pattern that she recognises. She recalls being caged like an animal and is forced to accept that this is the ship she arrived in, but despite this she still doesn’t trust Dorsai. There’s only person in her life that she trusts, and he isn’t here. She tells Dorsai the Professor is closer to her than anybody she’s ever met -- even her mum and dad -- and she’d trust him with her life completely. Just then, she hears the Professor’s voice calling her name from far away. Dorsai says he can only hear the animals moving around outside, but she’s sure she can hear the Professor and tells Dorsai to be quiet. She calls out to her friend, but there’s no reply. Eventually, Ace starts to doubt herself and accepts that she only heard what she wanted to hear. There’s no one else on the ship apart from the two of them...and the ghosts of the dead.
Dorsai leads Ace back through the jungle, but after a while he comes to a stop. He tells her there are tribers a kilometre away and moving in their direction. Tribers are the dominant life form on this moon, higher anthropoids like big apes, but two metres tall and with tusks -- and they’re completely hostile! Dorsai and Ace are 400 metres away from the compound, so they hurry back as fast as they can. They make it through the force field and Dorsai reactivates it, then he helps Ace back into the house. Dorsai explains that the tribers are territorial and they regard humans as intruders into their world. Ace says she knows what it feels like to be a misfit and she’s surprised when he tells her that it’s something they have in common. She can’t understand why he keeps protecting her and guesses that it’s because he’s alone here. She insists that the Professor will soon find her and warns him not to count on her being around for long.
Once she’s alone, Ace becomes ever more determined to get away. She knows Dorsai feeds her and worries about her, yet she’s convinced he’s just trying to mess with her head and is probably an amiable psycho. She hears the sound of piano music drifting in from the main room and joins Dorsai, encouraging him to continue playing. She’s been here for seven days now and she’s wondering whether any other ships pass this way, but he tells her Yentob Minor is too far from the space trade routes. Ace thinks that sounds rather “convenient“, but Dorsai says it’s actually very inconvenient for his friends. Ace thought he was alone here, but he says he never told her that. She accuses him of playing mind games, but he says if that’s true he’s not very good at it and doesn’t understand the rules. She asks him about his friends and he tells her that their names are Dr John Cusack and his wife Margaret, but they died and he buried them in the compound. He knows what she’s thinking and assures her that he didn’t kill them, he just buried them. This house is the remains of the Cusacks’ space vehicle, and Ace realises they must have crashed here too. It was a scientific scout ship and they made a new life for themselves here, using the raw material around them to make furniture. The piano is actually electronic, salvaged from a damaged instrument panel, and Dorsai learned to play when Mrs Cusack became too ill to do so herself. He plays now to remind himself of her, which he admits is curious as he never thought he’d become sentimental. Dorsai was Dr Cusack’s assistant, but because Mrs Cusack couldn’t have children, he eventually become like a son to them. Now he spends his time continuing their exo-biological work, studying the moon’s life systems. He sometimes finds it helpful to talk to the couple at night, and he wonders if that’s a sign of madness, but Ace tells him she also used to talk to her Nan’s grave when she was little. She opens up to Dorsai and tells him more about her childhood and how she was always getting into trouble with her mother, who she dismisses as a boozy old pregnant dog who only cared about herself. It was her Nan who looked after her mostly. Filled with distant memories, Ace decides to lie down for a while.
Ace is woken up by the sound of rapid bursts from the force field. She calls out to Dorsai, but the computer responds instead and advises her to stay inside. Dorsai enters the house and tells her the tribers are throwing rocks and broken branches against the dome of the defence barrier. Under normal circumstances they wouldn’t be able to break through, but he’s worried because the scout ship fusion generators can only produce a limited amount of energy per minute. Suddenly they see the tribers bring down a tree, which falls against the rim of the barrier and catches fire. The computer warns them that the power drain is increasing, so Dorsai orders all non-essential systems to be deactivated and a 15% reduction in life support so that power can be diverted instead to the force field. The tribers continue to go mad and Ace asks Dorsai if has any weapons, but unfortunately Dr Cusack disagreed with violence. At this rate, the barrier can only hold out for another two hours and forty-seven minutes...
Some time later, Dorsai tells Ace there are only a few juvenile male tribers still in the area, but the main group has moved away. This sort of thing happens once every two or three weeks and they attack the barrier at various points periodically to test for weaknesses. This group was led by a large silverback male and Dorsai could see from his eyes that he was intelligent. He thinks they’re a remarkable species, worthy of further study, but Ace tells him she couldn’t give a monkey's. Dorsai isn’t sure whether she made a joke or not, so he thanks her for showing concern for his safety, but she tells him she was only worried about protecting the guy who makes all the meals.
In a secret laboratory, Dorsai continues his experiments on a juvenile female triber. He records no after effects from the temporary reduction of life support so he begins an examination of her brain stem functions. For this procedure, the subject must remain semi-conscious. He approaches her with surgical instruments at the ready...
Ace is starting to become quite accustomed to her blindness and can easily find her way around her room. She reassures herself that if Dorsai enters the room, she can lock herself in the toilet without too much trouble. Dorsai calls out to her from the main living area and asks her to join him. He presents her with a stick with built-in detectors to prevent her colliding with the furniture or falling outside. He explains how it works -- there are three settings, one for detecting ground density, one for testing the power cell and one that acts as a proximity tester. He regards it as a temporary arrangement until her eyesight returns, then he offers to examiner her eyes again, but she refuses. He tells her he’ll be leaving for a while to continue with his exo-biology studies, but while he’s gone the house computer should be able to provide for her needs. As soon as he leaves, she begins cross-examining the computer and it confirms that they’re on Yentob Minor, which is three parsecs from the nearest space route. It also confirms everything else Dorsai told her, but she knows that he may have programmed the computer not to reveal anything. Instead, she asks it directly whether there’s anything it’s been instructed not to tell her. It confirms there is classified data that she’s not cleared to access, which includes personal details about Dorsai. She also discovers that Dorsai has taken with him the hand-held manual device that switches the compound barrier on and off. Suspecting there may be another one somewhere in the house, Ace asks for a list of areas that are off-limits to her, but the computer will only respond with the words ’Unit 3’. She asks the computer to make an interactive map that will show her how to get to the crash site, but it will take 36 hours to produce such a device.
In the jungle, Dorsai returns to Entrapment Area 2, but finds it empty. Even the juvenile tribers seem to be avoiding the bait, so he proceeds instead to Area 3, but that’s empty too. If he has no luck at the last location, he’s going to have to think of an alternative method for entrapment.
Ace asks the computer how many doors there are inside the living area and discovers there are four -- the main entry, two living quarters and a security door. She asks for directions to the security door and feels around for an entry coder. She spends time making some random combinations, then gives up and asks the computer to switch off the containment barrier, but it refuses. Rather than waste any more time, she decides to get in some practice on using the proximity stick.
When Dorsai returns to the camp she welcomes him home with exaggerated affection, and when he doesn’t respond, she points out that he doesn’t have much of a sense of humour. She thinks he’s more of the traditional boring scientist type, so nothing at all like the Professor. He asks whether she’s willing to co-operate yet with an examination of her eyes, especially as he needs to change the dressing if he’s to prevent it from becoming infected. Ace still isn’t ready for that, but says she might reconsider tomorrow.
Over dinner, Ace asks Dorsai if he’s even considered building a communicator, but he tells her none of the necessary systems survived the crash of the Bellerophon, their scout ship. She’s surprised that he couldn’t improvise, but he says they wouldn’t have the energy to transmit a powerful enough signal anyway. She thinks any signal would be better than none, but the fact remains they just don’t have the resources. In any case, Dorsai doesn’t seem to mind living here -- there’s power, shelter, work and a temperate climate. Ace points out there are no other people here, and she doesn’t count the Cusacks because they’re dead. Dorsai quotes Thomas Hardy and says the Cusacks are still alive in his memory, just as Ace’s Nan is alive in hers. She thinks it’s different because she still has people in her life, but Dorsai reminds her that she hasn’t spoken to her parents or her friends in years. She accuses him of turning the argument around and he realises for the first time that she thinks he’s deliberately trying to keep her here for his own benefit. He wonders how different this is to what her Professor does -- by travelling with her, he’s preventing her from having contact with the people who were important in her life, and she never stays long enough in one place to make any new friends. Dorsai believes the Professor controls the travel process and Ace admits that she’s asked to be taken home once or twice, but they don’t always end up in the right time or place. Dorsai wonders whether this makes the Professor incompetent, or whether there’s another reason? Ace becomes angry and swears that the Professor would never abandon her, but Dorsai points out that though she trusts him completely, she knows virtually nothing about him. He thinks she sounds very confused, but she doesn’t want to hear any more and she doesn’t have to explain or justify herself to him. She storms off to her room.
Dorsai visits the grave of Dr Cusack and his wife again with more fresh flowers. He tells them that Ace still seems uncomfortable and instead of accepting her situation, her feelings for the Professor keep clouding her judgement. At first he thought it was her blindness that accounted for her hostility, but she’s still afraid of him and he wonders if it’s something he’s said or done. He knows that if she was really determined to leave, he couldn’t stop her. He feeds her and takes care of her, but what more can he do?
Ace collects together some supplies, including food and vitamin tablets. She checks with the computer and is pleased to discover that the map she requested is ready. She picks up the cube and asks it for directions to the cargo ship. It seems to work as she intended, so all she has to do now is wait for the right opportunity... Some time later, Dorsai returns and calls for her -- but she leaps out and clubs him to the floor. Satisfied that he’s unconscious, she takes his remote control, switches off the barrier, and leaves the compound. She asks the cube for directions and the interactive map gives her step-by-step instructions into the jungle. When Dorsai recovers, the computer tells him he’s been out of action for 25 minutes. He reprogrammes a second barrier remote control and has the setting for the original one deleted from the computer.
Ace is now deep in the jungle, taking care to make sure she avoids any boggy terrain. She hears Dorsai calling her name and realises he can’t be far away. She takes cover as best she can and whispers to the cube to plot new directions. Unfortunately the altered course takes her straight into quicksand and she finds herself sinking rapidly into the mud. She calls out for help and Dorsai soon finds her. He urges her to stop struggling and passes out a branch for her to grab hold of. Eventually he manages to pull her to safety, but when she tells him she’s lost the interactive map, she realises she‘s given the game away. Dorsai says she can tell him all about it later, but she still wants him to take her to the crashed ship as this is the first place the Professor will look for her. Dorsai notes that her continued faith in the Professor is admirable, but warns that she won’t survive the night there as the tribers are on the move again. He tells her he can’t protect her there, but she insists she can look after herself. They hear the sound of aggressive tribers in the area, so Dorsai picks up the struggling Ace and carries her away, promising to debate the matter later. Before long Ace can hear the hum of the electro-magnetic barrier, but the tribers are getting nearer all the time. In the rush to get back to the compound safely, Dorsai drops Ace and she starts to panic as the apes gets nearer -- but then Dorsai offers her his hand and asks her to take it.
Safely inside the compound, Ace notices that Dorsai’s shirt is wet and she realises he must be bleeding. He tells her it’s messy, but not serious and he starts to clean the wound. Ace is filthy and takes a bath, then she hears Dorsai call out from the main living area, telling her the soup is ready. She joins him, but warns him he’s going to have to wait a long time if he’s expecting her to apologise. He asks her why she’s afraid of him and she tells him he’s creepy. He asks her what she means and in turn, she asks him if he has any idea what it’s like being blind. She feels his behaviour has been smothering, but Dorsai tells her he didn’t realise and he thought he was doing the right thing. She tells him she’s going to bed and when he says goodnight, she snaps at him and tells him she’s fed up with him being so polite and “goody-goody”. Frustrated, she storms off.
Ace wakes up when she hears the Professor’s voice calling her name. She blurts out that she’s had a terrible nightmare in which she was blind and there was a weird bloke with a computer butler and a jungle full of hostile apes. She asks the Professor why he’s looking at her like that, but he tells her she’s not really Ace. She thinks he’s trying to freak her out and tells him to stop messing around, but he simply tells her there’s something wrong here. She looks around and everything seems OK, with everything in the right place just as it ought to be. He asks her to join him by the mirror, but when she looks into it, she has no reflection. She finds herself trapped in the room and starts banging on the door, but the Professor tells her the game is over...and she lost. He then starts laughing maniacally and Ace begins to panic, screaming to be let out. Dorsai tries to comfort her and tells her she’s been dreaming, but she breaks down in tears, not sure whether she’s awake or asleep. Dorsai hugs her and she asks him why the Professor hasn’t come for her yet. She can’t live like this anymore and tells Dorsai she wishes he’d let her die.
Dorsai passes Ace a drink and tells her she had a rough night. She cried herself to sleep and he took the opportunity to change her dressing. He tries to get her to eat something, but she tells him to leave her alone, then she starts to cry again...
Sometime later, Dorsai is playing the piano again when Ace emerges from her room. She’s finally starting to accept that the Professor isn’t coming for her and she realises it’s time she faced the facts. She tells Dorsai she’s been a complete pregnant dog and she knows that he’s just been trying to help her. She smashed his plates, stole from him and even hit him over the head. He tells her that last night she even spat at him. She apologises and puts it down to delayed shock. She admits that she would have died out there without him, and she thanks him for everything. The question is -- what does she do now? Dorsai offers to take another look at her eyes, and this time she lets him. He tells her she has beautiful eyes and there doesn’t appear to be any tissue damage, therefore the optic nerve may simply be stunned. It’s been two weeks now, but if the flash was sufficiently powerful, the result can be unpredictable. Her sight might return gradually, or she might even wake up one morning and find she can see again. In the meantime, he says Dr Cusack has an excellent database filled with art, music, history and literature, but she says there’s no way she's going to allow the computer to recite Dickens at her all day. Ace wants to clear her head, so she asks Dorsai if he’d like to join her for a walk around the compound. Outside, she can smell the flowers -- something she hadn’t noticed before -- and Dorsai tells her Mrs Cusack used to keep local flora.
Several months pass and Ace begins to accept her new life. Dorsai starts teaching her to play the piano, and this is followed by lessons about the histories of the composers. Even literary works became games as each of them reads out an extract from a great book and the other tries to guess where it comes from. Ace starts telling Dorsai stories from the time she spent travelling with the Professor, and a pleasant walk around the compound becomes an evening ritual. On one such occasion, Ace notices for the first time how nice and hard his arm muscles are and she wonders what the rest of him is like. She asks him why she never knows what he’s thinking and he puts it down to the fact that they have different brains. Then one night, while Dorsai is outside checking the barrier, Ace activates one of the door codes and the computer tells her she has accessed level one clearance. Realising she must have done it by mistake, she finds herself faced with a moral dilemma. Although she feels as though she’s sneaking a look at someone’s private diary, the temptation is too great. She asks the computer to play back Dorsai’s log entries from the last few months... She skips through the earlier entries as they seem to confirm everything Dorsai has already told her about her medical condition and the state of their relationship, although she finds his reference to the need to modify her behaviour a bit cheeky. She then hears him make reference to the treatment he’s been giving her as an “exercise” and then he says her eyes have already begun their recovery. Shocked, she rips off the bandages around her eyes and discovers she can see! She storms outside the house to confront Dorsai -- and sees his face for the first time. Dorsai is an android...
Ace orders Dorsai to keep his distance. She can’t believe that she actually fancied a machine, but Dorsai asks her whether it really makes that much difference. She insists that it does as he’s not a real person, but he argues that he qualifies as a person even if he is an artificial life form. She dismisses him as a heap of circuits and bio-polymers and says he was built, not born, but Dorsai can’t understand why biology rather than technology should decide whether someone is alive or not. He says he is self-aware and is capable of both independent thought and action. He can also sense and comprehend, but Ace believes this is just his programming and she points out that he doesn’t have emotions. He accepts that point, but he says that in every other sense, he is human. He makes decisions based on information stored in his neural net, whereas she stores hers in her electro-chemical net, but their brain cortices are virtually identical. She thought he was real enough when she could only hear, feel and talk to him, but he hasn’t changed so he asks her whether she always judges by appearances. She changes tack and accuses him of literally keeping her in the dark. She tells him she’s heard his log entry and knows all about his experiment.
Dorsai takes Ace through the security door and shows her the real experiment that he’s been working on. She’s horrified -- it was bad enough when she though he was experimenting on her, but this is worse. He calls it his research, but she calls it butchery. It’s no wonder the tribers are so hostile if this is what he’s been doing to them! Dorsai explains that his traps are designed to catch only the weak and the sick, those that have been abandoned by the others. He cares for their needs, gives them a humane end and then collects the data. Ace argues that experiments like these are immoral and have been banned for decades, but Dorsai reminds her that in the early days of human medicine, doctors paid people like Burke and Hare to rob graves and those of high moral standard actually sponsored it to further scientific knowledge which led to life-saving techniques. Ace tells him he can’t use that as justification and even Burke and Hare ended up in prison eventually. Dorsai says it’s a question of necessity, not justification, but Ace wonders who will benefit from this data as no one ever comes here. Then it slowly dawns on her. These experiments were set up by Dr Cusack and his wife to give their lives purpose and keep them sane, but when they died, so did the purpose. This concept contradicts Dorsai’s directive, but Ace asks him to prove that he can truly comprehend by stopping the experiment and taking down the traps -- maybe then the tribers will leave them alone. Dorsai agrees to give her suggestion some consideration.
Later, Dorsai and Ace begin dismantling the traps outside the compound. They’re curious that the jungle is so still -- almost as if it’s waiting for something. They just have one last trap to do, but suddenly there’s a commotion and a flash. To Ace’s astonishment, the creature in the trap -- now hanging in the air above their heads -- turns out to be none other than the Professor, who’s been looking for her all this time. She and Dorsai help him get down and fortunately he seems to be all in one piece. Ace leads the Professor back to the compound and warns him about the electro-magnetic barrier. Dorsai invites them to sit down while he prepares some refreshment, then Ace begins to fill the Professor in on what’s been happening since they last met...
Dorsai visits the grave of Dr and Mrs Cusack and tells them the Professor has finally arrived. Ace might stay here, but he thinks it’s more likely she’ll want to continue her travels with her friend. He can offer her many times and places, whereas Dorsai can only offer her one. The Cusacks always said there were things he would learn as he grew, but without their presence there was no interaction and he stopped growing. Ace has shown him much, but in particular she‘s introduced him to a new concept -- self purpose.
Dorsai rejoins the others and asks Ace whether she plans to stay. She suggests that they could all leave together and they can drop him off at another planet where he can meet thousands of people. Dorsai reminds her that they’re both outsiders and he’s not sure there’s anywhere he can find acceptance. He believes he would be the subject of speculation or even fear, which breeds hate and violence, and he could never allow anyone to be harmed on his behalf. As far as he knows, he is unique and cybernetic engineers would want to study him to further their knowledge. His mind would be downloaded into a mainframe for analysis and he doesn’t think the essence of his memories would survive such a process. The Professor agrees that Dorsai can come with them if he wants, but Dorsai suggests they both rest here for the night and he can make his decision in the morning. He goes to prepare the evening meal, just as he’s done for the last few months.
Later that night, the Professor finds Dorsai standing alone in the exterior part of the compound. Dorsai knows that Ace will choose to go with the Professor, but they both agree she must be allowed to make her own decisions. The Professor asks if he can make use of the house computer, and Dorsai agrees.
The next morning, Ace finds the Professor still hard at work on the computer and he explains that they’ve been getting on famously. He’s discovered one or two things about Dorsai that she might find a little surprising... She’s amazed by what he tells her and before he can stop her, she goes rushing outside. Dorsai is still alone, having concluded that he no longer has any purpose or function. Ace tells him she’s just learned something interesting about the Bellerophon and she can’t believe it hadn’t occurred to her before. He’s been here on his own for over 101 years and ten months, but although he understands the meaning of the word ’alone’, he didn’t feel the reality until she arrived. He suspects the Cusacks deliberately didn’t give him the relevant human emotional component as a kindness, but in fact it means they only gave him half a life. He now knows he requires someone like Ace to provide the other half. Ace wonders if that means he’s in love with her, but he will only say that he’s become accustomed to her presence, and when regular interaction stops he’s aware of its absence. He says he was built for purpose and reason, but when his creators died, so did their directives. Their bodies will have passed into the soil by now, so their graves are as empty as their house. Ace has helped him to comprehend, but he now considers himself to be obsolete.
Dorsai purposefully strides straight into the electro-magnetic barrier, and after a few seconds the power drains away and he falls to the ground. Ace rushes over to him, but the damage to Dorsai is clearly irreparable. In a stilted mechanical voice, he tells her that he understands what she meant about being shut out and cut off, and now he also knows what it’s like to be blind. She pleads with him to conserve power, confident that the Professor will be able to fix him, but when the Professor joins them he tells her there’s nothing he can do. Ace breaks down in tears as Dorsai tries to speak for the last time. She holds his hand, but it’s too late and Dorsai’s functions slowly run down until there’s nothing left of him but an empty mechanical shell.
Later, Ace makes the final entry in the Bellerophon log. She leaves a message to anyone who might find this house and compound in the future. She explains that there are now three graves outside: one for Dr John Cusack, one for his wife, and one for the remains of their greatest achievement -- a sentient, artificial human -- but she asks whoever receives this message to let the dead rest in peace. Then she tells the computer to disengage systems and power down. She rejoins the Professor and asks him to take her home.