'Using a sledgehammer to crack a nut is a lot harder than you might think.' Miggea - a world on the very edge of reality. The cusp between this universe and the next. A point where space-time has worn thin, and is in danger of collapsing... And the venue for the grand finals of the competition to win the fabled Arrow of Law. The Doctor and Amy have joined the Terraphiles - a group obsessed with all aspects of Earth's history, and dedicated to re-enacting ancient sporting events. They are determined to win the Arrow. But just getting to Miggea proves tricky. Reality is collapsing, ships are disappearing, and Captain Cornelius and his pirates are looking for easy pickings. Even when they arrive, the Doctor and Amy's troubles won't be over. They have to find out who is so desperate to get the Arrow of Law that they will kill for it. And uncover the traitor on their own team. And win the contest fair and square. And, of course, they need to save the universe from total destruction.
