Better than Moby Dick?: Yes
This short novel--really more of a novella--begins with a bizarre premise. At the height of the Cold War, the Earth suddenly becomes flat. Instead of a spinning globe wheeling through space, all the continents and oceans of Earth are spread out on an enormous flat disc. And the disc is unfathomably huge: its surface area can hold billions of Earths. In the oceans beyond the continents of Earth lie strange continents peopled by unhuman beings.
Humanity has no idea how it has come to be transported to the disc, but the change has severe geopolitical consequences. The nuclear deterrence between the superpowers is based on the ability to launch missiles in a polar orbit; polar orbits no longer exist, and nuclear missiles from America can no longer reach the Soviet Union. Consequently, the Soviets overrun Europe, and extend communism across their continent.
Both superpowers explore the unknown continents on the disk. The Soviets send Yuri Gagarin off in a huge Ekranoplan (a ground-effect aircraft), on a five year cruise to "boldly go where no Soviet man has gone before, explore new worlds and look for new peoples, and to establish fraternal socialist relations with them." Gagarin's expedition discovers an eerie secret: there are other Earths on this disc, and one of these alternate Earths has been destroyed in a nuclear holocaust.
It's a pretty good book, and it's short enough to read in a couple of hours.
You can read Missile Gap online for free at Subterranean Press.