Spring, 1941. France has fallen but the Free French naval forces are in no mood to surrender. Royal Navy Sub-Lieutenant Harry Gilmour is also ready for action, despite the horrors of his first taste of submarine warfare.

When he is appointed as British Navy Liaison Officer aboard the Free French submarine Radegonde, he finds it anarchic, disorientating—and very French. Within its claustrophobic confines, suspicion and misunderstanding are rife.

So when Radegonde is sent on a mission to Martinique, it’s vital that these proud men learn to work together, especially as it seems everyone from Churchill to de Gaulle—not to mention Hitler—has a stake in the outcome.

Will Harry be able to navigate these dangerous waters safely and return with hard-won wisdom, or will old enemies arise to sink him?

David Black is a former Fleet Street journalist and television documentary producer. He spent much of his childhood a short walk from the Royal Navy Submarine Memorial at Lazaretto Point on the Firth of Clyde, and he grew up watching the passage of both US and Royal Navy submarines in and out of the Firth’s bases at Holy Loch and Faslane. As a boy, the lives of those underwater warriors captured his imagination. When he grew up, he discovered the truth was even more epic, and so followed the inspiration for his fictional submariner Harry Gilmour and a series of novels about his adventures across World War Two. David Black is also the author of a non-fiction book, Triad Takeover: A Terrifying Account of the Spread of Triad Crime in the West. He lives in Argyll.