After witnessing the sinking of his ship HMS Watchful, and seeing the officers and men he knew so well dead and dying, Commander John Hammond suffers a nervous breakdown and is admitted to hospital. Following extensive psychiatric treatment, he is finally considered fit to return to duty. However, doubts remain in his mind if he will ever really recover from the past. This is soon put to the test when, after being appointed commanding officer of HMS Simba, a Tribal Class destroyer, he is faced with a life or death decision while on convoy duty in the Mediterranean. Luckily, date intervenes to solve the problem; but when his ship is sent on convoy duty to Russia, facing the hazards of icebergs, U-boats and the Luftwaffe, Hammond has to decide on a daring course of action which, if successful, could save his ship and the lives of his crew. While the action in the story is based on actual events, as a counterpoint to death and destruction, the author describes raunchy runs ashore, matrimonial difficulties, romantic involvements and the humour and comradeship of the lower deck, which still prevails in today's navy.