The keeper's son / Hickam, Homer H.

Josh Thurlow returns to his Atlantic Ocean island home of Killakeet Island to command a Coast Guard unit and to continue his search for clues to the whereabouts of his brother who has been missing for seventeen years.

In 1941, Coast Guard patrolman Josh Thurlow, still struggling with guilt seventeen years after the disappearance of his younger brother, battles U-boats off the North Carolina coast unaware that one of the German captains may know his brother's whereabouts.