July 1945. Eighteen young British, Australian and New Zealand special forces from a top-secret underwater warfare unit prepare to undertake three audacious missions against the Japanese.

Using XE-craft midget submarines, the raiders will creep deep behind Japanese lines to sink two huge warships off Singapore and sever two vitally important undersea communications cables. Success will hasten ultimate victory over Japan; but if any of the men are captured they can expect a gruesome execution.

Can the Sea Devils overcome Japanese defences, mechanical failures, oxygen poisoning and submarine disasters to fulfil their missions? Mark Felton tells the true story of a band of young men living on raw courage, nerves and adrenalin as they attempt to pull off what could be the last great raid of World War Two.