The Chronophage (The Emperor's Library: Book Five)
by Frederick Kirchhoff
Sexually assaulted, Lim finds himself in the care of Jules, one of the Masters who, with the Army, rule Gort. Jules apprentices him to the goldsmith Falke, who is constructing the chronophage, a device that slows time. When Jules is threatened, they use the chronophage to help him escape, and thus begin adventures culminating in an extravagant theatrical performance that brings disaster to Gort.