“Full Circle” is an adventure of the eighteenth season, the first of the mini-arc known by the global title “The E-Space Trilogy”, which aired in 1980. It’s a four parts adventure written by Andrew Smith and directed by Peter Grimwade.

“The Armageddon Factor” is the sixth adventure of the sixteenth season, known by the global title “The Key to Time”, which aired in 1979. It follows “The Power of Kroll” and it’s a six parts adventure written by Bob Baker and Dave Martin and directed by Michael Hayes.

“The Power of Kroll” is the fifth adventure of the sixteenth season, known by the global title “The Key to Time”, which aired between the end of 1978 and the beginning of 1979. It follows “The Androids of Tara” and it’s a four parts adventure written by Robert Holmes and directed by Norman Stewart.

“The Androids of Tara” is the fourth adventure of the sixteenth season, known by the global title “The Key to Time”, which aired in 1978. It follows “The Stones of Blood” and it’s a four parts adventure written by David Fisher and directed by Michael Hayes.

“The Stones of Blood” is the third adventure of the sixteenth season, known by the global title “The Key to Time”, which aired in 1978. It follows “The Pirate Planet” and it’s a four parts adventure written by David Fisher and directed by Darrol Blake.