In an example of situational irony, Herbert encourages his father to use the monkey’s paw to wish for two hundred pounds and then dies in a tragic factory accident the next day, resulting in the company giving his parents a two-hundred-pound payout. While Herbert expects that the wish will lead his parents to happiness (as they could pay off their mortgage), it actually leads them to deep despair (as their beloved son is now dead).
The irony of this turn of events comes across in the following passage, in which Mr. White asks the representative of Herbert's company how much they would receive in compensation for their son’s death:
Mr White dropped his wife’s hand, and rising to his feet, gazed with a look of horror at his visitor. His dry lips shaped the words, “How much ?”
“Two hundred pounds,” was the answer.
Unconscious of his wife’s shriek, the old man smiled faintly, put out his hands like a sightless man, and dropped, a senseless heap, to the floor.
Here, Mr. and Mrs. White are both shocked at the ironic twist that their son may have died as a result of the wish he encouraged them to make—Mrs. White “shriek[s]” and Mr. White falls “like a senseless heap” to the floor. The irony here is more tragic than humorous, as Herbert’s parents must face the consequences for trying to meddle with their fates.
