A crew of interplanetary archaeologists is threatened when an alien creature impregnates one of their members, causing her to turn homicidal and murder them one by one.

Eight different people are invited to their 10-year high school reunion at their now-closed down high school where a former student, disfigured from a prank gone wrong, is there to seek revenge.

Helena loves Bertram, but he's of noble birth, while she's just a doctor's daughter. But Bertram is at the court of the King of France, who is ill, and Helena has a remedy that might cure him and win her the right to marry Bertram. But does Bertram want to marry her?

The Rani has returned with another malicious scientific scheme. Taking advantage of the post-regenerative trauma the recently regenerated and unstable Doctor is going through, she hopes to achieve control of an approaching asteroid composed entirely of strange matter. Can the Doctor figure out he is being used for the Rani's evil experiment, and what is behind the door the Rani won't allow him past?