The Eleven. A Time Lord whose previous personalities live on in his mind: arguing, plotting, jostling for supremacy... He is also Gallifrey's most dangerous criminal. And he has escaped.

The Doctor is recalled to his homeworld to lead the hunt. As they search the Capitol's corridors of power, the Academy halls and the cells of the highest security penitentiary, Liv realises the worst monsters may be among the Doctor's own people.

For inside his fractured mind, the Eleven has a plan. And its deadly consequences will extend through space and time...