The Battle of the Atlantic has entered its deadliest phase.

1941. Britain stands alone, dependent on the fragile lifeline of merchant convoys crossing the Atlantic. Beneath the waves, German U-boats wait to strike.

Flying long-range patrols in the cutting-edge Short Sunderland, Flight Lieutenant Douglas Norton and the crews of Coastal Command hunt the invisible enemy. Every mission is a gamble. Every sighting could save a convoy - or end in disaster.

But when intelligence uncovers a secret operation threatening to shatter Allied control of the Atlantic, Norton is drawn into a dangerous mission far beyond routine anti-submarine patrols. From the storm-lashed seas of the Mid-Atlantic to the uncertain politics of neutral Ireland, he must outwit ruthless enemies, expose hidden collaborators, and prevent a catastrophe that could tip the balance of the war.

With U-boats prowling beneath the waves, spies operating in the shadows, and Britain's survival hanging by a thread, failure is not an option.

A gripping World War II naval adventure packed with submarine warfare, aerial combat, espionage and authentic historical detail. Perfect for readers of Douglas Reeman, Alexander Fullerton, and Alistair MacLean.

This work was previously published as The Gap by Richard Nigel Stembridge.