In December 1941, just a week after Pearl Harbor, HG-76, a convoy of 32 merchant ships, left Gibraltar bound for Liverpool.

Commander Johnnie Walker was responsible for protecting them. He faced a daunting task, as a German wolfpack of U- boats was lying in wait for him. During the convoy’s 2,000-mile voyage it would be continually shadowed by enemy U-boats and aircraft, and attacked with relentless ferocity.

Until now the U-boats were winning the tonnage war in the Atlantic, sinking ships faster than the Allies could build them. If that continued, Britain would be brought to its knees. Convoy HG-76, though, had two game-changing advantages. The first was the presence among its escorts of the small carrier Audacity. While she only carried four fighters, they proved invaluable in the convoy’s defence. The second was Walker himself, an expert in anti-submarine warfare whose talents hadn’t yet been tested.

The Convoy combines the story of the technical and tactical developments that won the Battle of the Atlantic for the Allies, along with a narrative that reveals both the terror and the stubborn determination that defined the experiences of those who served on convoy duties.