To break the centuries-old stalemate in their war, the Movellans need the Doctor, as do the Daleks need Davros. The solution is simple, but neither side can see it, nor would the Doctor upset this perfect and unplanned peace they've achieved. Davros, though, is another matter.

Count Scarlioni has the Doctor, Romana and Duggan locked in his basement but the trio manage to escape and learn of the Count's experiments with time travel. Even more surprising are his multiple genuine copies of the Mona Lisa.