The story follows the unnamed protagonist and his irrational hatred of John Claverhouse, a man with a "moon-face".
The protagonist observes from a distance with glee as Claverhouse lights a stick of dynamite and throws it into the water.
Claverhouse runs from the dog in futility until "just as she caught up, he in full stride, and she leaping with nose at his knee, there was a sudden flash, a burst of smoke, a terrific detonation, and where man and dog had been the instant before there was naught to be seen but a big hole in the ground."
In July 1901, two pieces of fiction appeared within the same month: London's "Moon-Face", in the San Francisco Argonaut, and Frank Norris' "The Passing of Cock-eye Blacklock", in Century Magazine.
Newspapers showed the similarities between the stories, which London said were "quite different in manner of treatment, [but] patently the same in foundation and motive."