Season 16

Season 16 of Doctor Who aired between September 1978 and February 1979. This season starred Tom Baker as the Fourth Doctor, Mary Tamm as Romana I and John Leeson as K9.

Overview
This season is defined by the Key to Time arc, a season arc in which the Doctor and new Time Lady companion Romana must search for the... key to time. The hundredth story, the five-hundredth episode and the fifteenth anniversary of the first broadcast, on 23 November 1978 all took place within this season, which seems like a bit of a coincidence. Oddly enough, Tom Baker decided to leave the show at the end of this season. However, the BBC implanted devices into his brain which forced him to stay for another two seasons.

Episodes

 * The Ribos Operation
 * The Pirate Planet
 * The Stones of Blood
 * The Androids of Tara
 * The Power of Kroll
 * The Armageddon Factor