It's years since Private Investigator Annie Raymond set eyes on PC Jennifer Flanagan, yet here they are face to face because a rogue shipping container turned up in a recycling yard on the outskirts of Hull, and a man died. The grieving widow hurls accusations but too quickly backs off. Why is the container undocumented? How did it arrive unnoticed amid the forest of cameras and automated recognition systems? When Annie's paymasters start taking too close an interest in her present, and Jennifer's supervisors begin digging into her past, the two women are drawn into an uneasy alliance. Do they feel under surveillance because they're watching each other, or is it something more sinister?While Annie tries to protect her agency, in the myriad dockyards sprawled alongside the dark waters of the Humber, robotic systems swing gigantic steel containers with millimetre precision through the cold winter air.