The Doctor is given the task of reassembling the six parts of the Key to Time by the the White Guardian.
Trying to obtain the first segment of the Key to Time, the Doctor and Romana are swept up in an elaborate con.
Prisoners of the maniacal Graff Vynda K, the Doctor and Romana must break out and pursue the first segment.
The Doctor and Romana work desperately to obtain the segment of the Key to Time - and escape alive.
Instead of landing on Calufrax, they arrive on a different planet and encounter the Mentiads.
The Doctor and Romana encounter the telepathic Mentiads and Zanak's ruler, the half man, half robot Captain.
The Doctor has discovered the sinister truth about Zanak and solved the mystery of the missing planet.
Time is running out for the Doctor and Romana in their struggle to defeat the Captain.
The Doctor and Romana arrive at a circle of standing stones in the English countryside.
The quest for the Third Segment has landed the Doctor in the midst of a druidic cult centered on a stone circle.
Chased by blood-thirsty stones, the Doctor must find a way to rescue Romana.
The Doctor must play for time while Romana tries to discover just who Vivian Fey really is.
Arriving on the techno-Ruritanian world of Tara, Romana easily obtains the Fourth Segment...
The Doctor must employ a desperate gambit to keep the evil Grendel off the throne.
The Doctor must keep the android "king" running while Grendel plots to use Romana to destroy him.
Grendel plans two weddings and a funeral to cement his hold over Tara.
Searching for the Key to Time lands the Doctor and Romana in trouble on the third moon of Delta Magna.
Things look bleak for the Doctor and Romana, particularly when Kroll awakes.
The massive Kroll is awake and killing anyone in its path. And the swampies are determined to appease it.
The Doctor and Romana are trapped between the monstrous Kroll and the insane refinery commander.
The Doctor and Romana land in the midst of a brutal nuclear war between the planets Atrios and Zeos.
Swept up in an apocalyptic war, the Doctor must help the Marshall defend his planet.
The Doctor meets a new enemy, the Shadow, who wants the Key to Time.
There is a desperate gambit to prevent a massacre...while it is getting harder to tell friend from foe.
The Shadow appears to hold all the cards, but the Doctor has found an old friend.
The Doctor and the Shadow have their final confrontation to take control of the Key to Time.