The African Queen

Set at the beginning of WWI. German troops set fire to an African village, resulting in the death of an English missionary. His straightlaced sister Rose (Katharine Hepburn), now alone, is taken aboard a riverboat, the African Queen, by its gin-soaked Canadian skipper, Charlie Allnut (Humphrey Bogart). Allnut would love to sit out the war just drinking and smoking, but Rose convinces him otherwise; newly invigorated and desiring revenge, she persuades him to take her downriver where they will try to destroy a German U-boat using homemade torpedoes. Along the way, the unlikely pair falls in love.