A sensational first novel for a number of reasons. The important characters are all women. Specifically, four women perfect a time travel procedure; there is no emphasis on technology, the reality of time travel is treated as a matter-of-fact occurrence. Instead, as the title indicates, the story is about the psychological consequences of time travel. Future versions of an individual can co-exist. How do you cope with knowledge about your future self: who you marry, how you die? And finally, the book contains a cracking good mystery. Very entertaining.