Months on from his last investigation, and with Grace's team still reeling from the fallout, Roy must prove that a wealthy Brighton businessman has brutally murdered his wife.

A sinister inquiry into skeletal remains found in a forgotten Brighton storm drain takes Grace down a labyrinthine trail through the past.

When a body is dredged up from the seabed of the English Channel, it sets in motion a truly disturbing investigation which forces Grace to ask himself just how far anyone might go to save the ones they love.