This season saw the introduction of the Black and White Guardians as well as the companion Romana, who became only the second female Time Lord companion since Susan. This season is sometimes colloquially known as The Key to Time season after the story arc involving the Key to Time. Although not the first season to consist of linked stories (Season 8 in 1971 was the first, as all the stories that year featured the Master), it was the first to be recognised as having a series long arc. Although multi serial arcs would occur again, such a full- season experiment wouldn't be attempted again until
All episodes — The Key to Time
S16 E1The Ribos Operation (1)
Sep 2, 19786.725 min
The Magellanic Clouds, the planet Ribos, an unknown time. Ordered by the White Guardian to collect the pieces of the omnipotent Key to Time, The Doctor, K-9 and his new assistant Romana arrive. Collecting the first segment is not going to b
S16 E2The Ribos Operation (2)
Sep 9, 19786.625 min
Trying to obtain the first segment of the Key to Time, the Doctor and Romana are swept up in an elaborate con. The target – the homicidal Graff Vynda K.
S16 E3The Ribos Operation (3)
Sep 16, 19786.625 min
Prisoners of the maniacal Graff Vynda K, the Doctor and Romana must break out and pursue the first segment – even as Unstoff takes it into the most dangerous place on Ribos.
S16 E4The Ribos Operation (4)
Sep 23, 19786.625 min
Trapped in the catacombs between a mad warlord and ravenous monsters, the Doctor and Romana work desperately to obtain the segment of the Key to Time - and escape alive.
S16 E5The Pirate Planet (1)
Sep 30, 19787.425 min
Planet Zanak, unknown time. The Doctor and Romana are seeking the planet Calufrax where the second segment waits. They are in the right place and the right time… but on the wrong planet.
S16 E6The Pirate Planet (2)
Oct 7, 19787.725 min
The Doctor begins to investigate the mysteriously wealthy planet Zanak. Mentiads, a deranged Captain, strange omens, miraculous mines – what does it all mean? And what does it have to do with the Key to Time?
S16 E7The Pirate Planet (3)
Oct 14, 19787.625 min
The Mentiads take the Doctor, Romana and Kimus to a reunion with K9 and Mula, where they set about trying to defeat the Captain.
S16 E8The Pirate Planet (4)
Oct 21, 19787.425 min
The Captain and Xanxia work toward their secret goals. Both depends on the pirate planet consuming one more victim - Earth.
S16 E9The Stones of Blood (1)
Oct 28, 19787.825 min
England, the late 1970s. The Doctor and Romana arrive in search of the third segment. But the Tracer readings are erratic and something ominous is happening with an ancient stone circle...
S16 E10The Stones of Blood (2)
Nov 4, 19787.725 min
The quest for the Third Segment has landed the Doctor and Romana in the midst of a druidic cult centred on a stone circle. But the stones are not what they seem, and somewhere out there is a blood-thirsty Celtic goddess.
S16 E11The Stones of Blood (3)
Nov 11, 19787.425 min
Chased by blood-thirsty stones, the Doctor must find a way to rescue Romana. What awaits him in the theoretical absurdity of hyperspace?
S16 E12The Stones of Blood (4)
Nov 18, 19787.425 min
Facing a sentence of death from merciless justice machines, the Doctor must play for time while Romana tries to discover just who Vivian Fey really is.
S16 E13The Androids of Tara (1)
Nov 25, 19786.925 min
Arriving on Tara, Romana locates the fourth segment of the Key to Time with ease. But getting it away proves more difficult, as she is captured by the scheming Count Grendel who wants the throne of Tara for himself.
S16 E14The Androids of Tara (2)
Dec 2, 19786.625 min
The Doctor must employ a desperate gambit to keep the evil Grendel off the throne. And the Count has a new pawn to play - Romana.
S16 E15The Androids of Tara (3)
Dec 9, 19786.825 min
The battle for control of Tara turns into a duel of wits between the Doctor and Grendel. But the Count shows he has more treacherous tricks up his sleeve.
S16 E16The Androids of Tara (4)
Dec 16, 19786.825 min
Grendel plans two weddings and a funeral to cement his hold over Tara. The Doctor and K-9 race to foil him and save the Time Lady's life.
S16 E17The Power of Kroll (1)
Dec 23, 19786.125 min
The Third Moon of Delta Magna, The Future. The Doctor and Romana arrive in search of the fifth segment and are immediately swept up in a conflict between the crew of a new refinery and the embittered natives…
S16 E18The Power of Kroll (2)
Dec 30, 19785.925 min
The Doctor and Romana try to avoid being sacrificed to Kroll – just in time for the real monster to appear.
S16 E19The Power of Kroll (3)
Jan 6, 19795.725 min
The massive Kroll is awake and killing anyone in its path. And the swampies are determined to appease it – by sacrificing the Doctor and Romana.
S16 E20The Power of Kroll (4)
Jan 13, 19795.725 min
The Doctor and Romana are trapped between the monstrous Kroll and the insane refinery commander. And there is no sign of the fifth segment of the Key to Time.
S16 E21The Armageddon Factor (1)
Jan 20, 19796.725 min
Searching for the sixth segment, the Doctor and Romana land in the midst of a brutal nuclear war between the planets Atrios and Zeos.
S16 E22The Armageddon Factor (2)
Jan 27, 19796.725 min
Swept up in an apocalyptic war, the Doctor must help the Marshal defend his planet. But who or what controls the Marshal?
S16 E23The Armageddon Factor (3)
Feb 3, 19796.825 min
The Doctor meets a new enemy – the Shadow – who wants the Key to Time. And the Atrian-Zeon war is approaching an awful climax.
S16 E24The Armageddon Factor (4)
Feb 10, 19796.625 min
The Doctor is forced into a desperate gambit to prevent a massacre. But it is getting harder to tell friend from foe.
S16 E25The Armageddon Factor (5)
Feb 17, 19796.425 min
The Doctor and Romana finally venture into the Shadow's lair. The Shadow appears to hold all the cards but the Doctor has found an old friend.
S16 E26The Armageddon Factor (6)
Feb 24, 19796.725 min
The Doctor and the Shadow have their final confrontation to take control of the Key to Time. Completing it may entail an awful sacrifice. And the Black Guardian will do anything to obtain it and plunge the Universe into chaos.