The crew have their work cut out in preparation for a mission that could see them stay underwater for 100 days. On a more personal level, one young able seaman is called to a military tribunal before the captain's table
As Libyan rebels take up arms against the Gaddafi regime, the Turbulent has been diverted to join the NATO operation off the country's coast. The crew must be ready to fire her Tomahawk missiles at any time but there are problems on board - first a sewage leak, then a mission-threatening mechanical failure. Meanwhile, young submariner Buster is in trouble again and Richard awaits the captain's verdict on his leadership skills.
After taking part in NATO’s operation against the Gaddafi regime in Libya, HMS Turbulent is bound for the troubled waters of the Middle East. But before she gets there, she must navigate two dangerous 'choke points'. She’s the first British submarine to pass through the Suez Canal since the Egyptian revolution, so it's a nervous moment for all concerned. And at the Bab el Mendeb Strait between Somalia and the Yemen, she must conduct anti-piracy operations, while surfaced, through the night. Meanwhile, there are new recruits to be trained for action, and Richard and Timmo both find themselves at a turning point in their careers..