Tom Hazard has a dangerous secret. He may look like an ordinary 41-year-old, but owing to a rare condition, he's been alive for centuries. From Elizabethan England to Jazz Age Paris, Tom has seen a lot, and now craves an ordinary life. Always changing his identity to stay alive, Tom has the perfect cover working as a history teacher at a London comprehensive. Here he can teach the kids about wars and witch hunts as if he'd never witnessed them first-hand. The only thing Tom mustn't do is fall in love.