When the TARDIS touches down in London, 2006, schoolteachers Ian and Barbara are eager to explore their own future. But they have arrived in the middle of a war, a war that has left London a ruin.
Mistaken for vagrants, and with no way of proving otherwise, the Doctor's granddaughter and companions find themselves in the execution block on the Isle of Dogs. The Doctor has no choice but to help the military refine its ultimate weapon. The British Army has discovered time travel. And the consequences are already terrible.