Plot summary
Roger Shackleforth is desperately in love with Leila, an aloof woman who dismisses his affections. A stranger hands him the business card of an old professor named "A. Daemon", who can help with any problem. Roger visits Daemon, who after some resistance and suggestions that Roger will regret it, sells him a love potion for $1. Roger administers it in a glass of champagne; Leila falls madly in love with him and marries him, but soon her love becomes stifling.
Roger returns to the professor to buy poison for $1,000, all of Roger's savings. Daemon cautions Roger that the "glove cleaner" is odorless, tasteless, and completely undetectable, but must be used immediately and completely, or the user will lose his nerve and never again have the courage to try it. After Roger leaves, the professor muses, "First, the 'stimulant'... and then the 'chaser'."
When he gets home, Roger prepares a glass of champagne with the new potion. Just as he is about to give Leila her poisoned drink, she reveals—by showing him baby booties which she is knitting—that she is pregnant; Roger is shocked and drops both glasses. He says that he could not have gone through with it anyway, then passes out.
On Roger and Leila's terrace, Daemon relaxes with a cigar, and after puffing a smoke ring that turns into a heart, disappears.
Credits
Adapted from Wikipedia contributors, The Chaser (The Twilight Zone). Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.