Tim Lake grows up in Cornwall with his father James, mother Mary, uncle Desmond, and younger sister Katherine ("Kit Kat"). The morning after a less-than-great New Year’s Eve party, James tells Tim that the men of their family can travel back in time to moments they have lived before. Tim tests this by going back to the previous night’s party and changing a few events. When he returns, James discourages him from using his gift to acquire money or fame, and Tim decides to use it to improve his love life.

The following summer, Kit Kat's friend Charlotte visits. Although instantly smitten, Tim waits until the last day to tell her; she tells him he should have told her earlier. Tim travels back in time to tell Charlotte in the middle of the holiday, but she suggests he wait until her last day. Heartbroken, he realises that she is uninterested in him and time travel cannot change anyone's mind.