In the time travelling TARDIS, K-9 is playing chess with the Doctor on the floor. The Doctor mentions he saw Capablanca play chess against Alkhine in 1927 Buenos Aires but must have been called away from watching the game. K9 admits he has the records of all chess games from 1866 onward. Romana enters in a white gown like dress and puts the Key to Time tracer into the console, effecting a landing (some 400 years in time from the last landing). The Doctor reveals he wants a break from finding the Key to Time. K-9 deduces he will have "mate" in 11 moves and Romana sees he is right.

The TARDIS lands in the woods and the Doctor, looking at the scanner, thinks it is a peaceful place. Romana goes into the TARDIS clothing room to find an outfit suitable for Tara. She goes through the alphabetical wardrobe seeing Tahiti and Tally Ho. The Doctor is messing in a closet from the console room, dropping an oxygen mask and a colorful feather duster to find his fishing rod and reel. He tells the others that he Izzac Walton, writer of The Compleat Angler. Romana asks what fishing is. They go outside, Romana first. The Doctor tells her he is allowed to take 50 years off after a journey of 400 years and four par secs. When pressed for where "it says that", The Doctor makes something up, Time Lord Code Section 93, paragraph 2. Romana follows him to a stream where he admits he is only going to fish for an hour and that her shadow frightens the fish.

Romana leaves over rocks across the stream, using the tracer to find her way toward the fourth segment. She hears a strange bird above but something on the ground is tracking her. At the statue of a warrior atop a dragon creature, she finds the fourth segment -- the dragon creature's head is it. She uses the tracer to transform it but a fanged hairy beast attacks her. A man in a metal hat and face plate, uses his electric sabre to drive it off and tells her Romana is a pretty name. He has beasts on his grounds to hunt -- the woods are his and he is a Taran Knight, Lord of Castle Gracht and swordmaster to the Ninth Degree. He takes the fourth segment, telling her that it is law that she register the mineral. He notices the statue piece missing, a famous emblem of the family crest, supposedly giving good luck. He doesn't believe it and making the most out of Romana's hurt ankle, picks her up and carries her to his white horse. Romana doesn't recognize what it is.

The Doctor is asleep fishing, his hat over his eyes. An electric sword burns his hat and a Taran swordsman, Farrah is standing on his chest. The Doctor makes light of it. Behind them is an older man with a beard, Zadek, who tells him he and Farrah serve Prince Reynart, who is supposed to become Taran King soon. The Doctor asks, "What? Prince Reynart! I've never heard of him." The Doctor, after Farrah uses his sword threateningly again, takes the sword to examine it, throws it back to Farrah, who is stunned that the Doctor has done this so easily. He wants to kill the Doctor. Zadek asks the Doctor if he knows about androids and if he will help their android.

Grendel takes Romana on top the horse to Castle Gracht, telling her it is inescapable. Till, Grendel's dwarf hunchback manservant has the gates opened and then closed for them. Grendel tells him to get Madam Lamia, another servant.

In a lab, Madam Lamia checks out Romana. Lamia is an engineer and a peasant according to Grendel. Lamia and Grendel talk about Romana as if Romana is an android. Lamia uses her controls to put large restraints over Romana, who is lying on table. The pair plan to disassemble and cannibilize her parts! Grendel wants to keep the head, there might be some use for it. Lamia starts up a drill.

Zadek and Farrah take the Doctor to a large country house where Zadek leaves the Doctor with Farrah while getting Reynart from another room. The Doctor touches something on Farrah's shoulder, straightening it out but Farrah keeps cutting the Doctor's scarf. The Doctor threatens him, "If you keep burning my scarf, you'll have to kill me." He starts at Farrah but Zadek and Reynart arrive. The Doctor keeps complaining about his scarf. The Doctor moves to sit at the table but Farrah keeps annoying him with the electric sword.

If the Doctor will repair their android, Reynart will give him 1000 gold pieces. The Doctor answers, "Money, what do I care about money? 500 gold pieces, then." Reynart is kinder than Zadek and Farrah and tells the Doctor he will be free to leave. The Doctor starts to use this immediately trying to leave through the door but another guard is there. The Doctor must repair the android first.

Lamia sees Romana's swollen ankle is swollen for real. Romana is not an android. Romana says, "Brilliant."

The Doctor tries to give the android mouth to mouth resuscitation. He has seen better androids. Reynart shows him the mask it is to wearK-9that of his own face, Prince Reynart. According to astrologers, Reynart is to be made King but if he goes to the Coronation Room, the Count Grendel will kill him and if Reynart doesn't go, he will forfeit the kingship to Grendel. The only other heir to the throne is Princess Strella, who has vanished. The Doctor calls the robot -- George, figuring that it is a copy to draw the fire of the men of Grendel and Grendel himself, while the real Prince sneaks into the throne room. The Doctor says, "Well, it's been done before.” In the lab of Lamia, Romana hides the tracer up her sleeve. She is then given an injection in the arm by Lamia and passes out.

Farrah wakes the Doctor up so he can kill him, the Prince is gone, and Zadek believes the Doctor is not part of the plot, otherwise, the Doctor would have been gone, too. The Doctor looks at the android. Zadek and Farrah will go rescue the Prince, explaining to the Doctor about a warrior who does not fear death and will die with honor. The Doctor says, "Then he's an idiot!" The Doctor has a plan, crown the android; he then wants to go but they won't let him. He tells them he has better things to do than interfere in the politics of their pilfering little planet but Farrah threatens him with the sword again so he sees their way of thinking, "...on the other hand..." The Doctor goes outside with Farrah and blows K9's whistle, who hears it inside the TARDIS and comes out at once.

When K9 arrives, in the matter of their conversation, the Doctor kicks the android when Zadek calls K9 just a machine. Despite the Doctor's warnings, Farrah draws his sword and K9 burns Farrah's hand. K9 tells the Doctor that Mistress Romana has not returned. Zadek fears the direction Romana went in was into the hills of Grendel's estate. He believes Romana is in the hands of Count Grendel.

It has been 12 hours since Romana passed out. She wakes up now and tells Grendel she has no money. Grendel and Lamia bring her down to the dungeon to see into a cellK-9-there Princess Strella works on a puzzleK-9-she is the exact duplicate of Romana. Strella is to be Grendel's fiance, bride, and then deceased wife but Strella won't cooperate, therefore Grendel plans to use Romana in this. Lamia is treated badly by Grendel but he once showed her a certain courtesy. They take Romana in to see the wounded Prince Reynart where she explains she is not the Princess but Romana, a friend of the Doctor's. A guard, Kurster, holds her as a chain bond is put around her neck and they leave Romana locked up with the Prince.

The castle is 8 leagues from the country house. The Doctor sends K9 out. He, the android, Farrah, and Zadek go to the outer castle. Zadek goes to scout around. Farrah hopes he is careful, "He's not as young as he used to be." The Doctor asks, "Who is?" Farrah admits he can't talk to androids, feels uneasy around them. The Doctor makes note that some androids feel that way about humans. To conserve power, the Doctor has temporarily switched off the voice circuits to the android Prince copy. Zadek returns, having found a place to get in. Before the Doctor can stop Farrah, the blond young warrior throws a rock to distract a guard who holds a crossbow. Then Farrah uses a touch of his sabre against the man and he falls. The Doctor examines the guard's crossbow -- it fires energy bolts. He asks if the man will recover and Farrah tells him eventually in about an hour or so. The Doctor says, "Good." Farrah calls the crossbow a peasant's weapon.

In her lab, Lamia works on an android face and examines the 4th segment to the Key to Time, finding she cannot cut it or scratch it.

K9 approaches the castle from another side and his red eye tracker locates his MistressK-9Romana.

Two guards have grabbed Romana, taken her neck chain off, and dragged her out of the cell where the Prince weakens.

The Doctor, Zadek, and Farrah move through the underground tunnels, built when the plague hit and wiped out nine tenths of the Taran population. Androids replaced human workers to keep the planet going. The tunnels were so that the royal families could pass without fear of getting the plague from those above.

Four guards find the fallen, passed out guard and follow the Doctor, Farrah, and Zadek into the tunnel entrance.

Grendel tests out the throne he hopes to sit on soon. He goes back to the waiting room where he and Kurster talk about their plan's last moments. They have men dressed as peasants who will call for Grendel to take the kingship when the Prince doesn't show up. Grendel will reject the crown once for effect but no more than that; he cannot trust the Archimandrite to offer it to him more times than that.

The Archimandrite arrives with an outrageous, multi colored hat, and tells Grendel in the event the Prince does not show up and as he is not present yet and the time draws near, he may indeed choose the Count Grendel.

In the tunnels, the android Prince hits his head on the ceiling of the cave, twice. The four guards giving chase start firing their bolts. Farrah uses his shield. The Doctor runs to a panel, throws his own scarf out of his face, and pulls on a lever which is stuck, lever that will open into the throne room.

Grendel tells the Archimandrite that it is his guards and men that are around this castle now -- the palace guards are indisposed. The Archimandrite thinks it would be good to choose Grendel as king since it would avoid unpleasantness. It is time and the doors to the throne room are opened. Inside, Grendel and the others attending find the Prince on the throneK-9not knowing it is the android. The Doctor, Farrah, and Zadek are behind the throne; the Doctor manipulating the voice circuits and the other two holding the Prince up at various times.

Grendel whispers something to Kurster, who leaves.

The Strella the Doctor hit over the head and destroyed was an android, not real. He heard a spark on one of its circuits which tipped him off. The Doctor meets Count Grendel.

Romana is shoved into Lamia's lab where Lamia questions her about the 4th segment, not knowing what it is. Grendel arrives and asks Romana if she knows this Doctor and orders Lamia to prepare another android.

K9 returns to the Doctor and alerts his group that the Count has the Prince, the Princess, and Romana. The Doctor will repair the android by hooking the carbon circuit to the silicon circuit.

Lamia takes Romana's alpha brain waves and tells Grendel that Romana is not Taran. Romana had already told them both this. Grendel wants another android made that looks like Romana and wants it to be better than the first.

Three hours later: the Doctor and Zadek are testing the android Prince who goes on talking about monastic landsK-9religious orders are protected under the crown but this can be withdrawn if the King, wills it to be so. Zadek keeps forgetting it is the android and not the real Prince, and keeps asking for his leave. He admits to the Doctor that the android seems more intelligent than the real Prince. The Doctor tells him it is -- after all the Doctor programmed it. Zadek feels he can't trust androids. The Doctor tells him that some androids say that about people. Till arrives, sent by Grendel to speak to the Doctor, who acts like Till's friend and puts his arm around him, "We peasants have to stick together." As the two talk, Farrah wonders if they can trust the Doctor. Zadek wishes they knew more about him. When Farrah threatens to quietly draw his sword, K9 warns him not to. Till asks for safe conduct for Lamia and Grendel out of the country if they give him Romana. They will exchange the written permission for Romana at the Pavilion of the Summer Winds. The Doctor, after Till has gone, tells the others, "Do you notice how they always want you to go alone when you're walking into a trap."

Lamia and Grendel show Romana the android killing machine that looks like Romana. Till recorded the Doctor's voice and when the android hears the voice, it will fire a deadly purple ray from its stomach to kill. It can also kill in other ways as well. Romana takes a tool and hides it in her sleeve. Lamia makes a guard take Romana back to her cell and locks Romana up herself. Romana tries to reason with Lamia, telling her that Grendel is using her. Lamia already knows that. It is better than nothing for Lamia. Romana tries to get Lamia to release her, telling her that she and the Doctor will leave Tara. After Lamia leaves, Romana takes out the tool and goes to work on her neck chain, "Now how does the Doctor do this?"

K9 and the Doctor hide in bushes, looking onto the Pavilion of Summer Winds, a quaint cottage on Grendel's estate.

Romana wants to free Reynart too but he tells her to go get help from Zadek. Most of the guards are with Grendel now as the Doctor is at the pavilion. Romana calls a guard in as Reynart plays sick. The guard comes in and Reynart hits him with the hidden neck chain as Romana flees. Reynart passes out.

Kurster, his master Count Grendel, Lamia, and the android Romana are outside the Pavilion during the day even though the appointed time was midnight. Grendel kisses Lamia.

Romana sneaks to a horse, passing a tunnel exit, calling it Charger. She gets on it and tries to start it a scientific way. She kicks the sides and it goes, running down the tunnel and out the gate. A guard fires a crowbow energy bolt steam at her but misses.

Lamia checks out the inside of the Pavilion but is surprised when the door closes, the Doctor behind it. He has the permission slip rolled up in his hand, of course, Count Grendel will have to go into exile but the Doctor tells her it is a good and fair offer and throws it to her. Lamia calls out the door for Romana -- the android in reality unknown to the Doctor. She brings it in and wants the Doctor to bid greetings to his companion. K9 advises caution. As the Doctor bends down to talk to K9 saying something, the android Romana's beam misses him. Lamia sicks it on the Doctor, telling it to kill him. The Doctor gets the android in a position for K9 to shoot it in the back over and over, deactivating it. Grendel hears Lamia scream (or the android) and orders his men to start shooting at the Pavilion. Lamia runs out in panic and is hit by a crossbow bolt and dies. Grendel orders his men to stop and calls for the Doctor to surrender, telling him on his word he will let the Doctor live. Just seconds later, he whispers to Kurster to have all his men try to kill the Doctor the moment the Doctor exits. K9 advises the Doctor not to believe Grendel. The Doctor tells him, "You just leave it to me, K9, I know exactly what I'm doing." The Doctor opens the door and starts out but a volley of crossbow bolts fires at him and explode against the door. The Doctor runs back in, slams the door, opens it and sticks his head out, "LIAR!" More shots and he dashes back in to make K9 drill a way out the back. The two get out that way. Kurster spots them. Grendel offers 10,000 gold pieces to the man who shoots the Doctor. Romana arrives on a horse and goes past the Doctor, who yells to K9, "Everyone for himself, K9!" K9 shoots some of the men of Grendel. The Doctor gets on the horse with Romana, hoping she knows how to stop it.

The Doctor and Romana arrive the King's Cottage, Romana explaining to Farrah and Zadek she is not the Princess. Grendel arrives with a spear attached to a flag of truce. The Doctor takes Romana out back to another room. Grendel asks the King, the android how he is. It says, "I...am...well." The Doctor sticks his head out and laughs. Grendel laughs at him and asks about the charming Romana.

Grendel takes the Doctor to another smaller room beyond a curtain and calls him remarkable. The Doctor asks, "I am?" Grendel goes on, "...a man after my own heart." The Doctor says, "I am." Grendel goes on to explain that Zadek will kill him once his usefulness with the android has outplayed itself. Grendel wants there to be no more king, no android, no real Reynart. He will make the Doctor king. The Doctor strides out of the small room and tells Zadek, "The Count has just offered me the throne." That is treason. The Count flings his spear into the android, sparking it to uselessness and runs up and out the back way.

Zadek orders his commander to take six men and go after Grendel but the Doctor realizes it is useless. Farrah almost admires the man. Zadek should have killed him even if he was under a flag of truce. Grendel has nerve, they admit. His plan: become legal king of Tara. Romana will marry the King and then the king will be killed. Grendel, champion of widows and orphans, will marry the Romana (or Strella) and then kill her, too!

In his rooms, Grendel yells at servant Till. The clueless Archimandrite arrives and Grendel prepares him to perform a marriage, the king to Strella, then perform funeral rites and then another marriage!

A formal siege of Castle Gracht could take two years, the last one did. The Doctor proposes one man and his dog could get inside and open the gates.

Grendel goes to Princess Strella, who refuses to marry the king since it would mean his life would end at Grendel's hand if she does. She cares more for Reynart's life than her own. Grendel may kill her anyway since she is expendable now. Grendel goes to Romana and the King, telling Romana if she doesn't cooperate, Strella will die, very slowly.

Zadek and Farrah cast the Doctor and K9 off in a raft across the moat. Before he leaves, The Doctor refuses the sword from Farrah, "Too complicated for me." The Doctor oars the raft to a side across the moat.

The Archimandrite asks where the happy couple is, the dope he is. Till plans with Grendel should things go wrong.

As K9 talks, the Doctor shhs him. K9 starts lasering a small hole into the castle.

Romana is dressed like Strella. Grendel tells her this should be the happiest day of your life, "...it will also be your last." The king attacks him but Kurster, nearby, knocks him back.

The Doctor hurries K9 along, "A hamster with a blunt pen knife could do it quicker!" K9 tells the Doctor he ordered him to do it quietly. They hear wedding bells. The area opens and the Doctor goes in, tells K9 there are bound to be lots of steps inside. K9 should wait here, K9 telling the Doctor he is familiar with moats. The Doctor tells him he is an old sea dog, "Be careful, be careful." The Doctor goes into the hole and we hear, "Ohhhhhhhh." K9 calls his master, who pops his head out, "Shhhh!"

Romana and Reynart kneel before the Archimandrite and the marriage ceremony goes on. Reynart gets to say, "I do." Just as it is Romana's turn, the Doctor barges in and tells them she doesn't want to say, "I do." He introduces himself to the Archimandrite and prattles on and on about how he loves a good wedding and asks the Archimandrite if he has gotten to the part about just cause! Grendel calls the Doctor interfering and the Doctor agrees. Till punches the Doctor in the stomach but Grendel wants the Doctor to himself. Romana tells the Doctor that Grendel, who gives the Doctor a sabre, "He's the best swordsman on Tara." Grendel says, "I shall teach you a fencing lesson before you die," to the Doctor.

The Doctor starts out badly, getting his back nicked by the electric burst, and getting backed into corners but he does manages to knock Grendel's sword down. The Doctor kicks it back to Grendel.

Kurster, during the swordfight, leaves for the cellars. Romana spots him do this and follows. He had orders that if there was any trouble, he was to kill Strella.

Reynart stops Till from leaving and gets the manservant to tell him where the gate control is as the Doctor shouts out his plan to open it to Reynart while continuing to fight Grendel with sabres. Throwing Till, the King Reynart, opens the gate doors and the men (all four of them?) rush into the castle.

The Doctor fights Grendel out of the room as Zadek's men rush down a tunnel hall and electrify or stab two guards. The two swordfighters fight in another tunnel hallway.

Kurster threatens Strella, who was working on her stitching puzzle. Romana gets behind him and smashes the stitching frame over his head. Strella smashes a vase over Kurster's head to complete his passing out. She and Romana talk.

The Doctor fights Grendel up steps to the battlements outside. They hear the sounds of Zadek's men winning so the Doctor tells Grendel to surrender. He will never do that and pushes the Doctor into a bush. The Doctor grabs Grendel's face mask-helmet off. Grendel goes to the end of the roof, telling him that a Gracht never surrenders, "Next time, I shall not be so lenient!" He dives off the roof. As Grendel is swimming, the Doctor looks over the edge, "Grendel, you forgot your hat." The Doctor tosses it down to the man but Grendel ignores it.

In the marriage room, Farrah is thrown a sword by the Doctor who seems to depise it. Farrah complements the Doctor on his swordsmanship. To beat Count Grendel. The Doctor smiles, "Why was he supposed to be good?" Farrah laughs that the Doctor can jest after such a battle. The Doctor asks them where Romana is, "I have a pressing engagement on the other side of the galaxy." They suddenly realize Romana and Strella as well as Kurster are gone.

Reynart and the Doctor rush out of the room. In the cellar, Strella is showing Romana how to do the stitchwork puzzle. The door flies open, The Doctor, "Don't move! I said don't move!" He can't tell which one is Romana but sees there is no more trouble here. He introduces himself to Strella. He reminds Romana about the 4th segment. Romana runs out in her long wedding gown. The Doctor follows, leaving Strella and Reynart to reunite.