Scientists, politicians, and environmental activists may think they know how to solve global warming, but Will Heller, the protagonist of John Wray’s third novel, is certain he has the answer: he needs to have sex. The self-described “Lowboy” is, he believes, a walking furnace who is personally responsible for the melting icecaps and shifts in weather. Through coitus, he will cool his body and save the world from fiery destruction.

Lowboy, a jarring odyssey through its title character’s mind, takes place in the course of one day as we follow 16-year-old Will on a subway ride through New York City’s dark underbelly. Overmedicated and suffering from paranoid schizophrenia, Will has just escaped from a mental institution and is haunted by demons as he descends deeper and deeper into his personal hell (Wray, it seems, has chosen his characters’ names with particular care). Will is convinced the doctors at the mental hospital (or “school,” as he calls it) were the ones who “put degrees in my body.” Since then, his core temperature has been responsible for raising the Mean Global Temperature. He must now make himself “an airconditioned body.”

In the opening paragraphs, as Will boards the train, Wray unmistakably sets the stage for the phantasmagoric trip on which we’re about to embark:

Signs and tells were all around him. The floor was shivering and ticking beneath his feet and the bricktiled arches above the train beat the murmurings of the crowd into copper and aluminum foil. Every seat in the car had a person in it. Notes of music rang out as the doors closed behind him: C# first, then A. Sharp against both ears, like the tip of a pencil.

The boy is pursued by Detective Ali Lateef and Will’s mother, who may be just as mentally disturbed as her son. A doting parent, Violet Heller puts the “mother” in smother. She admits she might have aggravated Will’s illness, “But I didn’t cause it,” she insists.

Whatever the reason — genes, abuse in childhood, quick-to-medicate psychiatrists — the fact remains that Will poses a threat to society?even if he himself doesn’t see it that way. “The air is changing every single minute,” he tells a subway vagrant. “It’s thickening and flattening and building up speed. The air is getting hotter every day.” It’s up to him and him alone to cool the world.

He’d been given a calling: that was what it was called. It was a matter of consequence, a matter of urgency, a matter possibly of life and death. It was sharp and light and transparent as a syringe.

The comparisons with Holden Caulfield are inevitable and, to some degree, justified; but as it progresses, Lowboy bears less of a resemblance to The Catcher in the Rye than it does I am the Cheese, Robert Cormier’s classic novel that bends and flips narrative preconceptions as the story of a troubled young man’s bike ride unfolds. Like Cormier, Wray keeps the reader warily on edge, forcing us to question the reality of what’s being filtered through Will Heller’s perspective. Is a fellow passenger on the B train really a turbaned Sikh, or could he be nothing more than a discarded newspaper and plastic bag with which Will holds imaginary conversations? What are we to make of the times when Will speaks but no one else seems to hear him? Is he, in fact, actually on a subway — or is this tour of the under-city all in his fevered head? It’s just that sense of unease which Wray uses to keep the novel always slightly tipped off-balance.

Lowboy is less successful when the story shifts away from Will, especially in the chapters describing Detective Lateef’s pursuit of the teenage fugitive. Though Lateef is initially portrayed as the generic brand of quirky detective (one you’d rarely find in a squad room outside of television or literature) who likes “anagrams, acrostic poems, palindromic brainteasers and any cipher that could be broken with basic algebra,” he never fully comes to life, aside from the fact that he likes to sniff photocopies and bask in “the aroma of fresh toner.” He functions well as a Javert to Will’s Valjean, sweating and limping after the elusive, overheated boy; but beyond that, Ali Lateef lies flat on the page.

The novel’s best moments are those that allow readers to descend, like spelunkers rappelling in a dark cave, into Will’s frantic, frenetic mind. Here, Wray has crafted a stream-of-consciousness narrative that grows increasingly more frightening as we start to suspect the boy’s intentions may not be full of goodwill and charity to his fellow man. The hissing, shrieking subway tunnels reflect the cluttered, broken synapses of Will’s “cramped and claustrophobic brain.” Yet, even in his madness, there is the beauty of poetry:

He pictured late at night, following its ghost through its melancholy circuit, empty as the shell of a cicada. The thought of it made him lightheaded. He imagined the world that way, carbonized and disemboweled by fire, brittle and egglike, cycling through its orbit like an automated car. No more arclights, no more sidings, no more stations. No more passengers. His eyes tipped backward in their sockets and he stared into the dead starcluttered future. He was part of the future but only as a wisp of stellar gas. No life anywhere to speak of. No tunnel any longer and no hurry, no calling, no need for any kind of sacrifice. Only space and knowledge without end.

There is a certain amount of heartbreak at work alongside Will’s messianic complex. From the opening scene of a boy getting on a subway train to the novel’s final, shattering sentence, Wray has crafted a story of global proportions set in the confines of one person’s mind. As readers, we both fear and fear for Will as he moves “through a world transfigured and redeemed by sacrifice.”