A terrible new disease is spreading all around the world, making it's victims violent, flesh eating monsters. Nobody knows how to stop it or cure it and there seems to be no hope for humanity, as the disease strikes almost everybody, decimating people in their thousands.
A group of survivors camping in abandoned houses on the outskirts of London are told of a safe house in the middle of London, where people grow food, and there is order and organisation among them.
That safe house is the Tower of London.
But who can they trust as they embark on a journey all the way across London, where the infected lie in wait?