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

The novel is all about Det. Sgt. Charlotte Charlie Zailer and Det. Constable Simon Waterhouse. Charlie and Simon are getting engaged and Charlie is worried about how their marriage will turn out to be. The story is about Ruth Bussey, who was violently attacked many years earlier, now is seeing a guy named Aidan Seed.
Aidan confesses to Ruth that he has killed a lady Mary Trelease. But Ruth knows that Mary is alive and tries to convince Aidan that she is alive.Ruth goes to Charlie and tells her about this and on the same day, Aidan goes to Simon to tell him that he has killed the lady Ruth many years back.

The story is so confusing in the beginning but you still don't want to keep the novel down. I had to finish it before sleeping and read it till quite late in the night :) I liked it but people might find the style of writing confusing since it keeps switching from different people's perspectives. Everything does tie together in the end though.

Actually both of these books are the same - The Dead Lie Down and The Other Half Lives. I realised this after reading the novel. I think it was released in the UK as 'The Dead Lie Down'.