When the sky rips open somewhere over Dover, two objects hurtle out of the Vortex and crash-land in the sea. One is the TARDIS, out of control and freefalling - but the other, a mysterious crystalline sphere, is far more sinister... The Doctor and Donna are rescued and taken to a secret command centre in the Dover cliffs.
This book is part of the BBC Doctor Who: New Audio Books series and is book #2 in the series.