Proposed by Bob Baker and Dave Martin. It concerned two planets (Atrios and Zeos) at war over a catastrophic shift in their orbits. The war was being baited on a mysterious force. The Doctor was forced to make a temporary Key to Time to temporarily freeze both planets' armies. The Shadow (the mysterious force who was provoking the war) was planning to use the powers of the Key to time to pit the universe at war against everyone. His own shadow was the sixth segment. The Doctor thwarted the Shadow's plan by unfreezing both planet armies and giving each the co-ordinates of the Shadow's planet which just so happened to be in between both planets. Many elements of this story were recycled to create "The Armageddon Factor".