Edgar Lunt lives his life by scientific principles, that is, for every action there is a reaction. He believes that any pleasure he might have, will mean, somebody will suffer somewhere else. The result is he is not very happy at all, until Trevor, a young student,tries to show him a fresh outlook on life.
In the year 4000, the Daleks conspire to conquer the Solar System. Their scheme involves treachery at the highest levels and a weapon capable of destroying the very fabric of time. Only the Doctor and his friends can prevent catastrophe — and there is no guarantee they will escape with their lives...