The Earth has been moved, and it's a race against time as Donna and the Doctor try to find it before the Daleks destroy everything; they head for the Shadow Proclamation and the Medusa Cascade. Meanwhile on Earth a veritable bevy of ex-companions join together to contact the Doctor and take down the Daleks. Can Captain Jack, Sarah-Jane, Martha Jones and Rose find the Doctor in time...

The Earth has been overwhelmed and the universe faces dominion by the resurgent forces of a terrifying and limitless empire led by one of The Doctor's greatest enemies. Aiding the Time Lord in a final battle are several of his closest allies and companions, but for one of them, a price will be paid...