Time and Again

I keep hearing this one referenced in discussions of great time travel stories, and deservedly so. It's a perfect example of the genre. Vividly-told, readable, with an engaging mystery at its core and an ending that lands, as in all great time travel stories, with a perfect inevitability that leaves you breathless.

Especially interesting here is the mechanism of time travel: not via complicated machinery, but via a method of self-hypnosis. The idea being that what keeps us rooted in a specific time and place is our subconscious knowledge of all the tiny detail of that time and place, and that if those details can be temporarily erased, if we can live exactly as if we are living in a former time and remember nothing else, until we ourselves come to believe it completely– that we can open the door and find ourselves elsewhere and elsewhen.