Cover

Title Page

Dedication

For Lisa

Prologue

It begins with a comet.

Decades ago, an infrared telescope captured the thermal emission streaking through the solar system. Eventually it was determined to be 300.2 kilometers wide and orbiting the sun in an elongated ellipse that would bring it within five hundred thousand miles of Earth.

The moon, by comparison, is 238,900 miles away. This would be, scientists said, a beautiful light show that everyone should enjoy all the more, knowing that we’d narrowly escaped planetary annihilation.

The official name of the comet was P/2011 C9, but most people called it Cain, the surname of the astronomer who’d discovered it. Twenty years later, it burned into view and made its close pass by Earth.

People took off work. They gathered at soccer fields and in parking lots, on rooftops and along sidewalks, setting up lawn chairs and picnic blankets and grills and coolers as though readying for a fireworks display. Everyone suddenly owned a telescope. Vendors sold comet T-shirts and hats and key chains and plush stuffed toys. Surfers stacked up on beaches waiting for the big waves they believed would come from the gravitational flux. At least two cults killed themselves off, announcing this was the end of the world and the comet a gateway to the vault of heaven.

Professors and scientists and religious leaders became regular guests on cable news shows, where they talked about how comets had long been associated with meteorological and human disasters—tsunamis, earthquakes, and droughts. In 44 BC, when Caesar was assassinated, his soul was said to depart the Earth and join the comet flaming overhead. In AD 79, a comet’s arrival aligned with the eruption of Vesuvius. In AD 684, when Halley’s comet passed by, the Black Death broke out, and in 1066, when it made another appearance, William the Conqueror won the Battle of Hastings. Celestial judgment and providence. Or an instrument of the devil, as Pope Callixtus III called it.

“Heaven knows what awaits us,” one professor said. “It is a reminder of our irrelevant smallness and accidental existence in the universe, a glimpse of something violently outside the bounds of human existence, as close as you can come to seeing God.”

Local news reporters interviewed people on the streets. “I don’t know—it’s just kind of cool,” one man said. “Special. Once-in-a-lifetime sort of deal. You want to be able to say, I was there. It’s almost like we were living this two-dimensional life, and now there’s this sense of it being three-dimensional, if you know what I mean.”

Cain looked like a roughly drawn eye, some said. Or a glowing animal track. Or a slash mark in the fabric of space. A wandering star.

For a few days, the comet made night uncertain, hued with a swampy green light. And by day, the sky appeared twinned with suns. And then—gradually—the comet trailed farther and farther away, and people forgot all about it.