Set in the early days of WWII, Greyhound is the story of an international convoy of 37 Allied ships, led by captain Ernest Krause (Hanks) in his first command of a U.S. destroyer. The convoy ploughs through icy, submarine-infested North Atlantic seas while hotly pursued by wolf packs of Nazi U-boats.Faced with 48 hours of desperate peril, Captain Krause's hopeless mission is doomed to fail. But armed with extraordinary courage and grit, hope may just be on the horizon.