The Twin Dilemma - Part Four
The Doctor and Peri are reunited. The Doctor finally meets Mestor. He offers to help him. Mestor accepts the Doctor's offer and sends him and Peri back to help the Twins with the planet moving project.
The Doctor figures out what Mestor is hoping to do, disperse gastropod eggs throughout the universe. He tries to stop him with a frontal assault but Mestor's defenses prevent the Doctor from destroying him.
The Doctor and Azmael work together and destroy Mestor. Azmael dies, having previously used up all his regenerations. Lang decides to stay on Jaconda. The Doctor and Peri prepare to take the twins back to Earth in the TARDIS.
