The Better 'Ole plot
During the First World War, jovial soldier William 'Old Bill' Busby of Limey discovers that Russett, the major of his regiment, is a German spy who conspires with the local innkeeper Gaspard. The spies distrust Old Bill and poison his wine, but the spillage from dinner eats a hole in the floor causing Gaspard to fall into the cellar. Old Bill tries to save him and discovers a loft with carrier pigeons in the basement. Then, tipped off by Major Russett, the Germans bomb the opera house where Old Bill and Alfie are performing, but the duo manage to escape.