On a planet called Heaven, all hell is breaking loose.

Heaven is a cemetery for both humans and Draconians - a final place of rest for those lost during wartime. The Doctor arrives on a trivial mission - to find a book, or so he says - and Ace, wandering around Joycetown, becomes involved with a charismatic Traveller called Jan.

But the Doctor is strenuously opposed to the romance. What is he trying to prevent? Is he planning some more deadly game connected with the coffins revered by the mysterious Church of Vacuum and the unusual Arch that marks the location of a secret building below ground?

Archaeologist Bernice Summerfield thinks so. Her destiny is inextricably linked with that of the Doctor, but even she may not be able to save Ace from the Time Lord's plans.

This time, has the Doctor gone too far?