The Dead Lie Down // The Other Half Lives — Sophie Hannah

Ruth Bussey once did something wrong-horribly wrong-and was nearly destroyed by her punishment. Now, she has tentatively rebuilt her life and unexpectedly found love with a man named Aidan Seed. But Aidan also has a secret-he killed someone years ago, a woman named Mary Trelease. Ruth's horror turns to confusion when she realizes that she knows Mary Trelease, and Mary is very much alive.