From 188 Contes à régler
I had been warned that landing on P. Bis, a planet strictly parallel to our Earth, would have some rather surprising sensations. Seeing yourself duplicated and living a life absolutely identical to the one led on Earth could only be deeply unsettling - more unsettling, in fact, than I could have imagined. I found the exact copies of my friends and they all practiced the profession that I knew them to have, and their homes were just as familiar to me.
But I, on the other hand, was not exactly myself. Whereas I had always struggled to make a living as a novelist while juggling stupid, low-paying jobs, on P. Bis I was a brilliant journalist, very well-known and in great demand. And above all, I had not married the same woman, which probably explained this derailment in my career. I then had the idea of looking on Earth for the woman who had been mine on P. Bis, and I learned that she was still alive, but in the United States, married to an architect from Boston. At that point, I could no longer make sense of anything, and I was lost in a maze of absurd conjectures.
The explanation, however, was strikingly clear. On Earth, the young woman I had married at the end of the war would not have met this American, since he had died on June 6, 1944 when he landed on the beach of Arromanches. But on P. Bis, the landing had taken place on June 5, as initially planned.
Which had spared and killed other men.