The MSC Ruby is almost ready to leave Felixstowe. Seven remote-controlled gantry cranes are still at work, stacking containers in the ship’s bays. Some 11,000 containers pass through this port each day, making it Britain’s primary conduit to the arteries of global trade. The ­Ruby’s next call is Gran Canaria—then, the long run down the coast of Africa. Watching the scene, Adam Gibson, the lone police officer at the port whose job is finding stolen cars, sounds rueful: “There’s no way in hell I c...