The clock is ticking, as the Doctor and Amy find themselves trying to avert Chiyoko's creation and prevent a galactic war in Earth's future. The whole universe is hanging in the balance and the time vortex is close to complete collapse. Travelling between worlds that shouldn't exist and meeting long dead souls, the Doctor and Amy's toughest adventure could prove to be their last... The end of everything is approaching, at the hands of a little girl who wants to live forever.