In this humorous "mystery" a very prim and proper old man, Mr. Erwin Martin, works as a file clerk for a company called F & S, run by a Mr. Fitweiler. Mr. Martin is extremely organized, fastidious and has everything in order. He has worked for the firm for 22 years. He does not drink or smoke. He does not make mistakes. He is very methodical and precise. One night at a party, his boss Mr. Fitweiler meets a loud, obnoxious woman named Ulgine Barrows. She is the opposite of Martin - brassy, pushy, smokes, drinks. She rescues Fitweiler from an uncomfortable situation at the party and he rewards her by giving her a job. Several others in the firm quit over her hiring. She makes constant use of baseball phrases that usually make no sense and are not germane to the situations at hand (Are you sitting in the Catbird seat? Are you scraping the bottom of the barrel?). Mr. Martin cannot stand her, so he plans to "rub her out."
This leads the reader to believe that Martin is going to kill Ulgine Barrows. That is the dilemma. He cannot tolerate working with her. So he hatches this plan, and the foreshadowing is used to make the reader think that Martin is planning a fool-proof way of killing her. In his methodical way, Martin proceeds with his plan. Slowly but surely, step by step. He knows where she lives, he plans to arrive when he is sure she is alone, he buys cigarettes which he intends to use as a red herring - just take a few puffs of one, and rub it out in the ashtray, so that the investigators would think that someone had been visiting Ulgine Barrows and that this person had killed her. No one would suspect him, because everyone knew he did not smoke.
As he enters her apartment, the suspense builds but there is a hint of foreshadowing of the ending:
When Mrs. Barrows reappeared, carrying two highballs, Mr. Martin, standing there with his gloves on, became acutely conscious of the fantasy he had wrought. Cigarettes in his pocket, a drink prepared for him--it was all too grossly improbable. It was more than that; it was impossible. Somewhere in the back of his mind a vague idea stirred, sprouted.
The prior plan was "grossly improbable" - "impossible" even. But! In the back of his mind, he was getting another idea - a vague idea that perhaps would be better. This is the turning point of the story because Ulgine Barrows fixes him a drink, he only takes one sip, he lights a cigarette but does not smoke it, but instead, he begins talking against their employer and tells Ulgine Barrows he is going to blow up the company and refers to Mr. Fitweiler as an old bag. Ulgine Barrows throws him out and we learn at the end of the story that the next day, she reports the entire incident to Fitweiler, who does not believe her story. Why? Because it is all so "improbable"- "impossible" really (foreshadowing). She tells a fantastic story about Mr. Martin drinking, smoking and planning to kill Fitweiler. She must be nuts! Fitweiler fires her and tells Martin the entire story. Ulgine Barrows says in a final fit of rage, realizing what has happened:
"If you weren't such a drab, ordinary little man," she said, "I'd think you'd planned it all. Sticking your tongue out, saying you were sitting in the catbird seat, because you thought no one would believe me when I told it! My God, it's really too perfect!"