As the first female officer in Zurich's maritime police force, Rosa Zambrano has traded a career investigating serious crimes for the serenity of the water. But now the body of her fertility doctor has been dredged up from the blue depths of the lake.

Sent to help the team looking into his death, Rosa's search leads her from opulent villas to genetic research labs and an escort service on the outskirts of the city - and to four women, each of whom has rejected the hand she's been dealt.