Decompression by Juli Zeh
Jola is a beautiful and privileged soap star who wants very much to be taken seriously; her partner Theo is a middle-aged author with writers' block. In an attempt to further her career, Jola is determined to land the lead role in a new film about underwater photographer and model Lotte Hass.
To improve her chances, the couple travel to Lanzarote and hire diving instructor Sven, paying him a large sum for exclusive tuition. Sven is meticulously planning his most ambitious expedition yet - to an untouched wreck 100 metres down on the ocean floor. Diving calls for a cool head and, as a sinister love triangle develops, events rapidly get out of hand. But whose story do we trust - Sven's or Jola's?
Deliciously claustrophobic, smart, and unrelentingly intense, this psychological thriller with shades of Patricia Highsmith will leave readers gasping for air.