Shortly after regenerating the Doctor crashes on the planet Varrken, where the people are slowing being taken over by a mysterious presence. The Doctor must find himself and undercover what's really going on.
A solider, Joseph Brimicombe has returned wounded from the trenches of WW1 and begins to see ghosts as everyone sees them. Just the Doctor and Valer arrive.
The TARDIS is drawn off course, bringing the Doctor and his friends to one of the worst battles in WW1, the Doctor must find the source of the aberration, but it turns he's not the only who searching for it.
The Doctor and his friends travel to the place where Valer was created in order to find her missing memories, but they find an old enemy instead; who will bring the Doctor and his friends nothing but pain.
A strange meteorite has crashed onto Earth and from it, Scarecrows appear and they are searching for something. The Doctor and Penny must uncover what's going on.