The plot is simple. Charlie loves Minta, but when she catches him in a compromising (though innocent) situation with her maid she breaks off their engagement. Distraught, he returns home and takes poison -- or so he thinks. His butler has substituted water for the poison and stands by, finding the whole situation hilariously funny. For a Keystone short Cruel, Cruel Love is light on slapstick until the last minute or two. Most of the humor comes from Chaplin's hilariously melodramatic posturing. From the moment Minta rejects him he strikes one "tragic" pose after another, so overcome is he with the sheer AGONY of the situation. (Oddly, watching this I found myself reminded of high school; our hero's histrionics nicely capture the kind of self-dramatization indulged in by so many teenagers.) The funniest moment comes when Chaplin, under the impression he has taken poison, wildly hallucinates what the title card calls A Vision of His Destiny. This turns out to be a stylized, Expressionistic Hell, complete with demons who repeatedly hoist Charlie into the air with pitchforks. The stark black backdrop in this scene is suggestive of Chaplin's much later WWI Liberty Loan short, The Bond, but the wild-eyed close-ups of Charlie which precede and follow the sequence are unlike anything else in his work. This bit alone is worth the price of admission.
For many years Cruel, Cruel Love was believed to be a lost film, and during that time various reference books attributed the role of the butler to Chester Conklin. Viewing the film now, however, it's obvious that the butler is played by the much taller Edgar Kennedy, who is quite recognizable in a number of medium shots. His hair looks a little strange, dyed gray and combed over to make him resemble Mack Sennett, but when he rocks with laughter you just know it's Edgar Kennedy. And he looks like he's having the time of his life, too.