In Ankh-Morpork, right before the anniversary of the Battle of Cuzza—which took place long ago between dwarfs and trolls— a deep gnome is murdered. The dwarfs are sure it was the work of some troll. The trolls are sure it’s a setup. Tension between the two ethnic races is rising at a geometric pace; soon there will be riots in the city streets that could turn into war. And for Sam Vimes, commander of the city watch and Duke of Ankh, this is one headache after another. But whatever the circumstances are, at six in the evening he must read a book to young Sam—regardless of reasons and circumstances. It’s the law, and His Grace the Duke follows the laws without fail.