Doctor Who: The War Doctor: The Heart of Battle

Trapped in a citadel swarming with Daleks, the Time Lord rescue force must find a way to overcome insurmountable odds. With the Daleks apparently planning to rule the Null Zone, perhaps their thirst for universal conquest and victory has been quenched…
The War Doctor doesn’t believe so - but how can he prove it without destroying any chance of peace?
As the countdown to the destruction of Keska proceeds, a deadly choice must be made... A choice that will define this Doctor, and perhaps forever cast him in the role of 'monster'.