HMCS Lakeville has just undergone a refit in Nova Scotia. Lieutenant Commander Clive Belanger and his crew are hoping for assignment to escort duty on the North Atlantic run again, close to the action against the Wolf Packs. Belanger has a few scores to settle there. But the orders he is given at a late-night summons to the Admiral's office are far different. Top-secret plans have been uncovered to land an enemy agent, a Vichy French sympathizer, by submarine somewhere along the Gaspe coast. The British want him dead, the Americans want to use him and the Canadians desperately want to destroy the sub at all costs. Belanger and his small force have been ordered to intercept the sub as it enters the ice-choked Gulf of St. Lawrence and sink it. And this time they are ready. With the new, better radar and Asdic sets, fresh from training exercises and work-ups, the main force is well prepared now to hunt down the enemy. Success will be proof to all its critics that the Navy is doing its job, proof that it's payback time against the deadly ship hunters. "