Parts: 6
Writer: Malcolm Hulke
Airdates: 24 February 1973 - 31 March 1973
Production Code: QQQ
Megalomaniac of the Week: the Master
Creature Feature: Draconians, Ogrons, Daleks
Story: The twenty-sixth century is a precarious time to live in. Two great empires, Earth and Draconia, are expanding through the galaxy, and the peace between them is maintained by the mutual agreement of a boundary across which neither party shall cross. But Draconians have been coming into Earth space, attacking their ships and stealing their cargo. The Draconians disavow all knowledge of this - instead, they claim that it is Earth who is attacking their ships!
Into this unstable situation come the Doctor and Jo, who arrive on board a cargo freighter moments before it is approached by a mysterious ship. Jo thinks she sees it change shape outside the window, but cannot be sure. When she and the Doctor go exploring, they are found by one of the crew...who, for some reason, believes them to be marauding Draconians, and has them locked up.
When the freighter is attacked and boarded, the Doctor and Jo realize that the situation is more complex than anyone knows. For the freighter is not boarded by enemy Draconians...it is boarded by Ogrons. But who are the Ogrons working for, and to what ultimate goal? The Doctor must convince the empires to trust him and work together to uncover the culprit, or else a space war will break out that could cost millions of lives...