The Time Traveler's Wife by Audrey Niffenegger. The story of Henry, a time-traveler who has no control over when and where he disappears through time, and Clare, his wife. The time travel aspect adds an interesting twist to a really sweet love story.
Tick tock goes the clock And what now shall we play ? Tick tock goes the clock Now summer’s gone away ? Tick tock goes the clock And what then shall we see ? Tick tock until the day That thou shalt marry me