John Arnatt

A slimy gossip columnist is killed and it's up to Simon to find the true murderer from the list of subjects.

Leela is concerned by the Doctor's strange behaviour when, after a secret meeting with aliens, he returns to Gallifrey and abruptly stakes his claim on the Time Lord presidency.

A dangerous game of hide and seek begins inside the TARDIS when the Sontarans get in.

A 15th century prayer volume disappears from a sealed casket inside the locked safe belonging to an Oxford Don. An illusionist is called in to demonstrate how the book can disappear from a locked safe, when the supernatural is suspected.

Authorities become alarmed when they realize parts of an atomic bomb are found among the baggage from a crashed airliner. The Invisible man is tasked with finding out the source of the parts.