The dilemma of the twins

After regeneration, the Doctor begins to behave erratically. In the wardrobe, he picks up a bright suit. Peri tells him that he cannot go out in such an outfit that he perceives it as an insult.

The twins Romulus and Rem Silvestov are visited by a mysterious old man named Professor Edgeworth and kidnaps them on a ship in outer space. Edgeworth contacts his boss, the slug Mestor, who demands that the twins be sent to Titan 3. The twin father, after learning about the abduction, contacts the authorities, and Commander Lang goes for the kidnappers. He finds the right vessel, which is considered missing, but that goes into hyperspace.

Meanwhile, the Doctor, considering Peri an alien spy, tries to strangle her, but sees his face in the mirror and lets her go. She tells him that he tried to kill her, and the Doctor denies this at first, but then, seeing her frightened face, decides to become a hermit on Titan 3. Upon arrival, they find Lang unconscious and take him to the TARDIS, where he reports that he the detachment was destroyed, and considers the Doctor responsible for this. Peri tries to convince Lang that the Doctor saved him, but he faints. The doctor refuses to save the commander, worrying about his life, but reluctantly agrees.

Romulus and Remus try to send a distress signal, but they are caught for it, and Edgeworth forces them to perform calculations without the use of electronics, Mestor threatens to destroy their minds if they do not do their job.

On the scanner, Doctor and Peri see the building, which is strange for an uninhabited asteroid. Leaving Lang, they find a tunnel leading to the building, but on the way they stumble upon two aliens with weapons. The doctor begs them not to kill, and they are taken to Edgeworth, in which the Doctor recognizes Azmael, an old friend, the chief of Dzhakonda, but is filled with disgust, having learned that it was he who abducted the twins. Azmael teleports along with aliens and twins, locking travelers in the building and leaving the self-destruction mechanism, but the Doctor and Peri manage to escape.

The TARDIS arrives at Dzhakonda, but instead of paradise, he sees only a desert covered with traces of giant gastropods. The doctor, fearing for his life, refuses to go to the castle, but still agrees to take Lang there. In the corridors they see murals with the history of the planet, including mythical slugs, which have now become a reality.

Azmael explains to the twins that Mestor has seized power and is going to drag the two nearest planets into the orbit of Dzhakonda, and calculations are needed to stabilize their orbits. The doctor, arriving at the laboratory, requires an explanation. Meanwhile, Peri is caught and delivered to Mestor. Doctors also soon catch, and he offers his help to Mestor, because the slightest mistake can lead to disaster. He reports that the planets will be placed in different time zones using technology stolen from Azmael. He finds out that because of this there will be an explosion of a star, which will spread the eggs of gastropods throughout the universe, and they will begin the conquest.

Mestor transfers his mind to Azmael's body, and the Doctor destroys his body with acid. Azmael, being on the last regeneration, regenerates, which kills him. The doctor and Peri return to the TARDIS, Lang remains on Jackond to help with the restructuring. When Peri says that the Doctor has become rude, he reminds her that he is an alien with different values ​​and customs and: "No matter what happens, I'm a Doctor ... do you like it or not!".

This is the first episode featuring Colin Baker as the Sixth Doctor. The actor has already appeared in the series in the series " Arch of Infinity " in the role of Maxil. The cruelty of the Doctor is explained by the fact that the creators were going to change his character in a better way over time.