The girlfriend of Charlie (here sporting a two-pronged mustache) mistakenly believes he has been flirting with her maid and says she never wants to see him again. By the time she realizes her mistake, Charlie has taken what he believes to be poison and thinks he is about to die. He’s put right, the woman takes him back, and everyone left standing at movie’s end gets drop-kicked by Charlie for no reason.
Story-wise, that’s about it. Chaplin mugs him it up as you’ve never seen, before or since, in a vain effort to convince us of the story’s hilarity.