As soon as Gino and Denton flew around the Moon, radio contact with the Earth disappeared. Throughout North America, city lights disappeared, and the continent was completely black. And upon returning to their homeland, they found themselves in a completely different world, where the Americans are at war with Nazi Germany, Einstein is alive, and Roosevelt died in the first year of his presidency. This story is included in the “Amazing Inventions” section of the book “50 x 50.” Harry Harrison's comments on the section title: “Yes, of course, it's all about them, isn't it? Thanks mainly to these inventions, science fiction has lived and developed throughout its history. After all, SF is the only literary genre in which an idea—or a machine—can act as the hero. And here are some very atypical heroes ... "First published in November 1963 in Amazing Stories.