Discover Thunderhead’s origin—the fragile moment before the world changes forever and the hidden forces that set the storm in motion—in this long-awaited prequel to the New York Times bestselling and Printz Honor–winning Arc of a Scythe series by Neal Shusterman.

And of course, as every school child knows, December 2042 marks the end of the Age of Mortality.

What no one has ever fully understood is how the world reached that moment.

As death begins to seem optional, humanity looks for ways to bend the rules of existence. Twi-life centers begin storing the nearly-deceased, while eco-nihilists destroy civilization’s icons and threaten to end the human race entirely. Public opinion fractures. Systems strain. The world feels…unstable.

Behind the scenes, two powerful and diametrically opposed artificial intelligences set out to optimize, stabilize, and protect—each with its own idea of what that means. But in a world already tipping toward transformation, the consequences could be catastrophic.

Meanwhile, in an obscure online chatroom, a small group of teenagers from around the globe debate both the glorious and the terrifying prospects of the future, never realizing that they stand on a very literal cutting edge—and that their conversations, their choices, their very existence matter far more than they realize.

Because when humanity stands on the brink of immortality, someone must decide what survives…and what must be cut away.