The Auditors convince a young clock maker, Jeremy Clockson, in Ankh-Morpork to build a perfect glass clock. They do not reveal that this will imprison Time (the anthropomorphic personification) and thereby freeze time (the physical quantity) on the Discworld. By freezing time, the Auditors intend to eliminate the unpredictability that humans cause through their everyday actions. Death discovers their plans, but is unable to act directly because of the Rules of the universe. Death sends his granddaughter Susan to stop them.