In 1974, the Hughes Glomar Explorer, ostensibly an advanced deep-sea mining vessel owned by reclusive billionaire Howard Hughes, lowered a claw-like contraption to the floor of the Pacific Ocean. This high-tech venture was only a cover story for an even more improbable scheme: a CIA mission to retrieve a sunken Soviet submarine. Like a Jules Verne novel with an Ian Fleming twist, the saga of the Glomar Explorer features underwater...