Deep Harbour by Tove Alsterdal

As the spring warmth melts the ice, divers search the wreckage at the bottom of the Ångermanland River - but the murdered man they recover was put there much more recently than the historic artefacts they were seeking. Local Detective Eira Sjödin, newly pregnant and not talking about it, is proud to be put in charge of the investigation - until she discovers the man's identity, and the evidence begins to point towards her own family. As Eira works to piece together the truth from the long-buried evidence and her mother's fragmented memories, she isn't sure she is prepared for the revelations this truth might unleash.