Commander Ernest Krause, a U.S. Navy career officer, has never commanded a ship across the North Atlantic from the United States to England. In the early days of World War II, Krause is tasked with taking command of a destroyer-class boat called the USS Keeling. Known also as Greyhound over radio code, the Keeling and its crew must protect a convoy of 37 ships from groups of German Nazi U-boats known as wolfpacks. Krause must find the strength and courage to help his crew and the brave souls on the other ships navigate treacherous waters while he struggles with feelings of inferiority.