The TARDIS crew is still missing Susan Foreman when the ship lands on a planet the Doctor eventually recognises as Dido, a world he has visited before. The trio soon encounter two survivors of a space crash, Vicki and Bennett, who are awaiting a rescue ship, due to arrive in three days time. Vicki and Bennett live in fear of Koquillion, a bipedal inhabitant of Dido, which is st... (展开全部)