From the Booker Prize-winning author of Possession comes a disturbing novel portraying a sibling rivalry which compels us to reconsider the uses and misuses of imagination.

When they were little girls, Cassandra and Julia played a game in which they entered an alternate world modeled on the landscapes of Arthurian romance. Now the sisters are grown, and hostile strangers-until a figure from their past, a man they once both loved and suffered over, reenters their lives.