In 1975, Daniel Eakins, a young college student, is visited by his "Uncle Jim". Uncle Jim offers to increase Daniel's monthly allowance for living expenses as long as Daniel promises to keep a diary. Shortly after, Uncle Jim dies, and Daniel inherits a "Timebelt" from him that allows the wearer to travel through time. Daniel quickly learns how to use the Timebelt and makes a few short jumps into his own future. He meets an alternate version of himself, who goes by "Don," who accompanies him to a race-track where the pair make a fortune betting on horse-racing. The following day, Daniel realises that it is his turn to act as Don and guide his younger self through the previous day at the races; through this and other events the time-travelling Daniel learns more about the belt, about the nature of the 'timestream', and about his personal identity.