If the stars should appear one night in a thousand years, how would men believe and adore, and preserve for many generations the remembrance of the city of God!

—Ralph Waldo Emerson

In 1941, Astounding Science Fiction editor John W. Campbell suggested Isaac Asimov should write a short story inspired by the quote above. What if humanity had never seen the stars? In both the famous short story (anthologized over fifty times in various collections) and the lesser known novel, Nightfall proposes the idea that the night sky could drive one literally insane.

The short story takes place on a planet orbiting six suns. At any given time, the six suns light every inch of the world’s surface. A group of scientists make a terrifying discovery: once every two thousand years, a celestial event plunges the planet into darkness. Much like the “psychohistorians” in Asimov’s Foundation, the scientists in Nightfall know their civilization is quickly coming to an end because the inhabitants of the planet are not prepared to see the heavens.

The story is unsettling. It doesn’t play on the fear itself, but the fragile nature of sanity when faced with the unknown. The last line of the story is chilling.

You could say the novel version, co-written with Robert Silverberg in the 1990s, dilutes that final line by telling us what happens next. That isn’t to say it’s not worth your time; Asimov and Silverberg mange to conjure unforgettable images of mass hysteria, including the widespread conflagration that naturally results from this brand of madness. When darkness reveals the stars, the people of the story burn everything they can get their hands on in an effort to make it light again.

The novel begins years before the events outlined in the short story. We get to know many of the characters: a psychologist who is treating patients who have been exposed to darkness, an archaeologist who discovers several civilizations in the past have burned to the ground with remarkable regularity, and the astronomer who realizes nightfall is coming.

The titular event takes place about midway through the book, more or less exactly as it happened in the short story. The last third of the book is about the aftermath, in which most of the world’s survivors are irreversibly insane. At one point, one of the main characters observes a group of men desperately trying to uproot a tree with their bare hands. That’s an image that sticks.

The original title of this post was Nightfall VS Nightfall, but it wasn’t fair to compare the two. They are separate entities written at different times in Asimov’s life. The novel will likely never be considered a classic if only because it retreads familiar territory. I highly recommend reading the short story first, then trying out the novel years after you’ve ruminated over the original ending.

In Isaac Asimov’s The Gods Themselves, which curiously begins with Chapter 6, chemist Frederick Hallam has discovered plutonium-186… sitting on a desk in his laboratory. It turns out that aliens from a parallel universe have discovered that plutonium is a powerful source of energy whereas tungsten steel is a powerful energy source in theirs. What the human characters set up with the aliens (“para-men”) is a free energy trade: they get our tungsten, we get their plutonium. Although there is the distinct possibility that pumping resources back and forth will lead to disaster, humanity is too addicted to care. Who’d want to give up free energy?

Isaac Asimov, like many golden age science fiction writers, is known for relying on a utilitarian narrative to convey grand ideas, but here he steps out of his comfort zone and creates something unusually literary. In his memoirs, he refers to it as “writing above my head.” For the first time he writes something which belongs to the new wave science fiction of the 60s and 70s. New wave was experimental, risque, and anything but golden age.

Following Chapter 6: Chapter 1, more of Chapter 6, Chapter 2, and so on. When Chapter 6 finally concludes, you understand why Asimov arranged the novel this way. Just when you get comfortable with the human characters—poof!—Asimov shifts gears and focuses entirely on the gods themselves: the so-called para-men who occupy roughly one third of the novel’s attention. This is the best part.

The abstract para-men are not your run-of-the-mill aliens. They come in two categories: the hard ones and the soft ones. The soft ones are divided into three sexes: parental, emotional, and rational, and mating requires no fewer than all three. The good doctor does something he’s never done before: he writes about sex, though their sex is vastly different than ours. (Asimov himself complains about his sometimes laughable characterizations of sexuality in the aforementioned memoirs.)

Despite Asimov’s departure from his usual style, you never forget he’s the man who masterminded it. He’s far too modest when it comes to the quality of his writing, but with The Gods Themselves he shouldn’t be. Asimov is a great science fiction writer. He has said this is his best novel. I can see why.