 Earth becomes the battlefield for the greatest and deadliest war of all time, as the Daleks and the Cybermen clash with the whole universe at stake. The Doctor and Rose, reunited with old friends and Cybermen experts Mickey and Jake, race to find a way to bring the war to an end before it brings about the destruction of the whole of space and time. But the Doctor soon faces an even bigger dilemma - could ending the war mean the death of Rose?