The Doctor apparently decides that his friends need time to relax after their traumatic experiences on Detrios, and thus takes them to the home of the People, a Dyson sphere built by a race so technologically advanced that they’ve had to sign a non-aggression pact with the Time Lords. Under the terms of the Treaty, which the Doctor helped to negotiate, he is regarded as a free agent and the Time Lords thus cannot be held responsible for his actions. For their part, the People have agreed not to pursue research into temporal technology, and to avoid the galaxy known as Mutter’s Spiral (the one containing Earth). The Doctor and his friends move into a deserted villa for the duration of their stay on the Worldsphere, and the Doctor places his TARDIS in a separate time interface to prevent God -- the operating system of the Worldsphere, an intelligence far too complex to be called a computer -- from succumbing to temptation and attempting to study it.
Following a particularly spectacular thunderstorm on the night after their arrival, the Doctor’s companions soon settle in and begin to enjoy a peaceful vacation. Benny befriends saRa!qava, a baker from the nearby village of iSanti Jeni, and Chris becomes romantically involved with saRa!qava’s daughter Dep. Even Roz begins to relax and open up to the Doctor, who seems to understand her desire to get away from her narrow-minded aristocratic family and make a difference in the world. But for now, only the Doctor knows that he didn’t choose this destination at random. On a tropical beach nearby, his friend, the drone intelligence aM!xitsa, has been keeping a feral woman under observation. The woman has nearly assimilated all of the alien vegetable matter which was inserted into her genetic structure, and the Doctor fears that she’s becoming too dangerous. She may have to be dealt with permanently.
SaRa!qava invites the Doctor and his companions to a fancy-dress party at the Windmills, a power facility set up above the village for aesthetic purposes. Although saRa!qava had given instructions not to serve anyone the memory enhancer flashback, Roz somehow gets hold of some and begins to relive uncomfortable memories from her past, including her execution of a shapeshifter which had taken on her appearance, and the death of her former partner Martle. In the process, she strikes up a conversation with a war veteran named feLixi, who understands her pain; he fought in the People’s war with an insect race, and although he knew that he could stop whenever he wanted to, that nobody would think less of him for it and that his experiences would change him forever, he nevertheless kept fighting, even after his lover was killed.
Chris and Dep play an electronic hunting game which is interrupted by a discharge from the Windmill’s power cells. By that time they’ve become more interested in each other, and they return to the villa to pursue their interest, only to be interrupted by kiKhali and agRaven, two agents from the ship !C-Mel. !C-Mel has noted that God seems to be devoting an unprecedented amount of attention to a single problem, and wants to know what it is and if it has anything to do with a recent death. During the recent thunderstorm, a drone named vi!Cari was struck by lightning and killed -- but it was a war drone, built with top-of-the-line defenses, and such an accident should have been impossible. Nobody really liked vi!Cari, who had become withdrawn and moody after its organic partner was killed during the war; it tended to collect other people’s secrets and brood over them, and it’s widely believed that it deliberately caused the microtsunami which destroyed the artist beRut’s seaside mural, just out of spite. Before kiKhali and agRaven realise that they’ve lost control of the conversation, the Doctor has agreed to help them investigate the possible murder, in fact intending to keep God’s attention away from the woman at the cove. kiKhali suspects that God is also trying to keep the Doctor occupied, either to collect more data on Time Lords’ behavioural patterns, or to get him killed.
Since God was only conducting routine surveillance on the night of the thunderstorm, it has an incomplete sensor record and is unable to explain why vi!Cari was out in the heart of the storm at the time of its death. The Doctor has Chris fly him out to the location of the death in a biplane, and returns convinced that the drone was murdered. He is unable to explain why vi!Cari was out in the storm, but he believes that someone found a way to modulate the lightning bolts of the storm in such a way that one strike remodulated vi!Cari’s defensive shielding and allowed a second strike to kill it.
The woman at the cove suffers a nightmare about a nameless man threatening to put her back into the toybox, and runs to the villa for shelter, catching am!Xitsa off guard. By the time it catches up to her and gets her back to the cove, Benny has seen her, and has recognised her as Kadiatu Lethbridge-Stewart. The Doctor admits that he tracked down Kadiatu before meeting Chris and Roz, and placed her here to keep her under observation somewhere safe; by the time he located her she had become feral, and had slaughtered the entire crew of an 18th-century slaving ship. As a genetically engineered killer, she has been hardwired to kill at the first perception of danger, and the enhancements made to her by Ship have given her a great knowledge of temporal mechanics -- and as a potential agent of chaos, she may attract the attention of powerful trans-temporal entities which intend to interfere in the course of history. To prevent this, the Doctor may have no choice but to kill her. Benny is appalled and refuses to permit this, and the Doctor thus puts the choice in her hands; he gives her all of the data at his disposal, and two days to decide whether Kadiatu will live or die. Benny finds the decision harder than she’d expected, and the responsibility gives her bad dreams, but in the end she decides that Kadiatu must be allowed to live -- despite the risk that her decision to save one life has condemned countless billions to death.
As the Doctor exists outside the normal flow of Time, his presence makes linear predictions all but impossible. !C-Mel thus nearly convinces the other ships to make a pre-emptive strike against Gallifrey, claiming that the Doctor must be acting as an agent provocateur for the Time Lords. The Doctor, realising the danger, sends Chris fishing while he speaks with the ships and manages to convince them that he’s not here to start a war. When the ships stand down, he returns to the sphere to find that although Chris and feLixi caught an intelligent fish they then let it go. Irritated, the Doctor catches it again and this time questions it, and it confirms his suspicions; someone did indeed drop a depth charge to create the microtsunami which washed away beRut’s mural. The Doctor theorises that vi!Cari went out into the storm with its shields lowered in order to search for evidence of the bomb and prove that it did not commit such an antisocial act. The ultimate penalty on the Worldsphere is social ostracism; on a world populated by over three trillion people, this is the closest thing imaginable to a death sentence.
Roz and Chris attempt to interrogate the ships, and Roz is profoundly irritated when the S-Lioness delights in showing off its superiority by answering her questions before she asks them. Both vi!Cari and feLixi had served on the S-Lioness during the war, and, like many veterans, they suffered from their experiences; one ship, the R-Vene, even had to be disassembled after two of its crew were killed and it destroyed an entire planet in a fit of rage. When Roz informs the Doctor of what she’s learned, he theorises that the R-Vene may not have been destroyed at all; perhaps XR(N)IG, the Xeno Relations (Normalisation) Interest Group, disguised it and set it up with a new identity. Vi!Cari once served upon the R-Vene, and it was known to collect other people’s secrets; perhaps it discovered the truth, and this is why it was murdered. Roz shares her discoveries with feLixi, and they make love in the wilderness area of the sphere.
While shopping with Benny, saRa!qava admits that she too had a motive to kill vi!Cari. Dep’s father doesn’t know she exists; saRa!qava had an unrequited crush on him, and thus she seduced him and stole his genetic blueprint to father her child. On the Worldsphere this is a crime punishable by ostracism. Benny advises saRa!qava to tell the Doctor, who agrees to meet her on an isolated area of the beach where nobody will overhear her confession -- but when he and Benny arrive for the meeting, they are attacked by tiny non-sentient drones programmed to chew through anything in their path. The Doctor and Benny hold off the attack long enough for God to notice what’s happening and send help. The Doctor assures the horrified saRa!qava that he doesn’t think she’s responsible; only a ship would have the resources to construct such an elaborate weapon. It must have tapped her call, and if it’s trying to kill the Doctor, he must be close to the truth.
Sensing changes in Kadiatu’s behaviour, am!Xitsa attempts to scan her brain, but it isn’t expecting her to modify her brain-wave patterns to strike back at him telepathically. By the time it recovers from the attack she’s fled from the cove and run to iSanti Jeni, where she paints graffiti over beRut’s new mural, provoking the furious artist to attack her. The Doctor, Roz, Chris and Benny arrive too late -- but she does not respond to his attack in kind, and they realise that she’s managed to overcome her genetic programming. She will no longer kill indiscriminately at the first sign of danger. Realising that she’s free, she begins to dance in celebration, and the people of iSanti Jeni join in. Later, Benny realises that she and Kadiatu share an unconscious telepathic link due to their association with the Doctor -- and Benny’s agonising over her decision, and her eventual choice to let Kadiatu live, filtered through into Kadiatu’s subconscious and helped Kadiatu to reprogramme her own brain.
As the Doctor and his companions relax after the exhausting dance, they realise that the Windmills must be the source of the blast which killed vi!Cari -- which explains the discharge that occurred during Chris and Dep’s game. Roz lets her friends go on ahead to investigate, as it has occurred to her that the moody vi!Cari may have kept a diary of its thoughts. When she confronts S-Lioness, one of vi!Cari’s few friends, the ship admits that vi!Cari had given it the diary, but that the ship was too frightened to read it. S-Lioness gives the diary to Roz, but !C-Mel sees her leaving with it and attacks, taking Roz and its entire crew hostage and entering the sphere to ensure that the other ships can’t fire upon it. Once inside, it admits that it is the R-Vene, and demands that the Doctor grant it political asylum; otherwise it will detonate its own power core, releasing enough radiation to kill all three trillion inhabitants of the Worldsphere. The Doctor convinces it to trade its hostages for himself, and once aboard he offers to negotiate telepathically with it. He then attacks it the same way that Kadiatu attacked am!Xitsu, using his mind as a weapon to disable the !C-Mel and dropping a microfusion grenade into its generator while its defenses are down. He and Roz escape moments before the mortally damaged ship breaks up.
Later that night, Roz confronts feLixi, having realised that the lover he lost during the war was vi!Cari’s partner, and that he has wanted vi!Cari dead ever since -- even though vi!Cari hated itself for its failure and had withdrawn from the People’s society because of it. It was feLixi who convinced !C-Mel that vi!Cari knew its secret, and although !C-Mel constructed the device which turned the Windmills into an undetectable weapon, it was feLixi who actually pulled the metaphorical trigger. When he learned that the notorious Doctor was on the Worldsphere, he feared that he would become involved in the investigation, and thus slipped flashback into the party and seduced Roz in order to keep an eye on the Doctor’s investigation. Roz realises that feLixi has genuinely come to love her, but it’s too late; he’s committed murder and used her to cover up his crimes. Now that the truth has been revealed, he will be ostracised from the People’s society, and nobody in the sphere will speak to him, ever again, for the rest of his life.
The Doctor gives Kadiatu an injection of Time Lord genetic coding which will complete her trans-temporal evolution. She is now capable of surviving and understanding the complexities of time-travel, and she intends to build a time machine of her own and explore the Universe with am!Xitsa as her companion, to act as God’s unofficial backup should the Time Lords ever break the Treaty. The Doctor and his friends remain on the Worldsphere for a few more days while Chris and Dep finish their work on an ornithopter and take it for one glorious ride, but then the Doctor announces that it’s time for them to go. Dep bids farewell to Chris without telling him that she’s pregnant with his child, and the Doctor summons the TARDIS back to this time frame and departs with his friends.
There is a story of a clever hare named Tsuro who was cast out by his own people, and who thus made friends with the other animals and protected them from the terrors of the world. But of all the threats he encountered, none was more dangerous than Danhamakatu the snake. Through a clever trick Tsuro freed the Leopard which Danhamakatu had sought to make its servant, and Danhamakatu vowed revenge. One day in the future, when Tsuro is least expecting it, Danhamakatu will take the life of one of his friends...
Source: Cameron Dixon