The boozing smoking cussing captain of a tramp steamer Charlie Allnut (Humphrey Bogart) saves prim & proper Rose Sayer (Katharine Hepburn) after her brother is killed by German soldiers at the beginning of World War I in Africa Many quarrels later the two set sail on the Ulonga-Bora in order to sabotage a German ship Based on the 1935 novel by CS Forester