The black hole of the Atlantic, October 1941

In mid-October 1941, convoy SC-48 makes its laborious way toward Great Britain, heavily laden with provisions, fuel, and matériel destined for an England still under siege. Departed from North America, the gathering of merchant ships follows the great North Atlantic route, the most vital and the most murderous of the war, the one on which the very survival of the United Kingdom depends. The Canadian escort commander knows that his convoy is entering the most dreaded zone of the passage.

For south of Iceland opens the "black hole" of the Atlantic, a vast corridor beyond the coverage of land-based aircraft, including those from Newfoundland. With no eyes in the sky, the escorts sail blind, dependent solely on their sonars and their lookouts. Intelligence and intercepts report that a wolfpack of U-boats has gathered directly across the convoy's route, lurking in the grey immensity. Night falls, the sea swells, the wind rises.

On the bridge, the commander scans the darkness where submarines he cannot see prowl. Canadian and American escorts are steaming up as reinforcements through the swell, but his units remain few against a wolfpack whose strength and exact position he does not know. Every minute counts before the first torpedoes find their target. He must decide without delay on the course to take.