The Watch have the sword, and with it they could wield the force of the Noble Dragon. Vimes would much rather no one had power on that scale. The Watch must trek through the Unreal Estate to destroy the sword in a magical lake. Carcer isn't far behind.
BBC America: The Watch have the sword, with it they could wield the force of the Noble Dragon. Vimes, would much rather no-one had power on that scale. The Watch must trek through the Unreal Estate to destroy the sword in a magical lake. Carcer isn't far behind.