It is 1962, and Marta Khoury, a trailblazing marine archaeologist, has travelled to Cairnroch, a small island off the east coast of Scotland. An arctic shipwreck containing the remains of a famous Victorian explorer has been towed back to the island at the behest of his wealthy descendants. Marta's job is to retrieve valuable artefacts from the vessel, deep beneath the freezing Scottish waters. But on her first dive, Marta becomes convinced she has seen a ghostly figure lurking in the wreckage. When Marta discovers objects from the vessel have inexplicably disappeared, she must work to...