It's the present day, and London is not a safe place. Donna Noble and the Tenth Doctor have discovered that people have been mysteriously disappearing, and to make things more complicated, a man named Laurence Falls is building something so dangerous it could wipe out the human race. What is he building, and how is that connected to all the disappearances? One thing's for certain: if Larry uses what he is building, the Doctor will die.
14 parts