Sayonara. The world's largest Liquid Natural Gas tanker. She represents a huge and risky investment for Heritage Mariner. The first vessel of this size to sail without a crew, using only computer control and millimetre-precise GPS positioning, she is programmed to dock automatically in Japan. Her cargo has the potential of fifty-five atom bombs, which will power the construction of the floating city of Kujukuri thirty-five miles west of Tokyo. But four days before docking, a group of pirates goes aboard, breaks into her secure areas, hacks her computers and takes control. Richard Mariner has ninety-nine hours to assemble a team and retake Sayonara in an increasingly desperate, danger-filled race against time to save his ship, protect his company and safeguard one of the most densely populated areas on earth.