The Old Vengeful by Anthony Price
When David Audley, that most subtle of Intelligence chiefs, sends his insubordinate protege Paul Mitchell off to investigate a KGB operation by researching a long-forgotten naval engagement off France in 1812, it doesn't look to Mitchell as if it will lead anywhere. But the fate of the crew of the Vengeful has more than a few surprises in store for Mitchell and suddenly the past throws a dazzling and very dangerous light on the present.