I can't really remember the original incident that sets off this wonderful chain of mishaps and myriads of slapstick action. It's been a while since I watched it, and what definitively remains is the image of Keaton being chased by an enormous army of increasingly disgruntled police men. This one didn't have the melancholy of the other Keatons that I enjoyed so much. But in terms of physical action there is so much going on, that it got even hard to follow sometimes.
Maybe I need a re-watch of this one sometimes.