Lancashire bootmaker Henry Horatio Hobson (Charles Laughton) keeps a tight rein on his three daughters, until his eldest, Maggie (Brenda De Banzie), marries his assistant Willie Mossop (John Mills) and sets him up in his own bootmaking firm. To Hobson's consternation, Willie has soon become his father-in-law's main business rival.

William Fitch (Will Hay, in his last film) is a disbarred barrister now summoned to court to face charges of sending begging letters. Falling back on his legal skills, Fitch manages to make mincemeat of the cross examining lawyer, Claude Bobbington (Claude Hulbert), and is found not guilty. However, this lucky streak does not last for long; a madman Fitch helped put in prison years earlier has now escaped, and is out for revenge. Fitch turns to Claude for help, but the pair fail to convince the constabulary that there is a real threat to Fitch's life, and are forced to track down the convict themselves.