The year is 1944, and Lieutenant Harry Gilmour is recovering in Beirut from an ill-fated British campaign to seize the Greek Islands.
After four years at sea, he is expecting a shore job as his next appointment. Instead, a flash signal from C-in-C Mediterranean arrives: Report to Alexandria and assume command of HM Submarine Saraband.
His new command has just arrived there en route to the Indian Ocean and the war against Japan. But there has been trouble on board, 'Conduct prejudicial to naval discipline,' and the skipper and first lieutenant have been summarily removed. Now it's up to Harry Gilmour to pick up the pieces.
With a sullen, uncooperative crew, Harry must navigate Japanese convoy routes through the shallow, treacherous waters of the Malay Archipelago. There, endless, sweltering hunts for targets through the island chains leave Saraband's crew even more exhausted and demoralised. Yet, if they are to survive against an Imperial Japanese Navy growing in anti-submarine expertise, Harry must turn them into a taut fighting machine.
Because waiting for them, as the war in the Far East grinds towards its final conclusion, is a mission as daring and audacious as it is vital. One that could deliver the Royal Navy's most spectacular success of the war.