Happy Ending is a 1949 short story by Henry Kuttner.
Plot summary
"James Kelvin pushed the button on the device the robot had given him. He was instantly transported to the chemist with the red moustache, who exclaimed, 'Where have you been? I patented those medicinal formulas you gave me, and they are easily worth several millions of dollars. We will both be healthy, famous and rich!'" This was the happy ending to the story of that name about James Kelvin (by Henry Kuttner, 1949). But it is also the first paragraph of the story! Now it continues with the beginning of his tale, and by the end of that beginning, the reader receives a nasty jolt, as every assumption of the happy ending is turned inside out by the truth.
