The real reason was that he was her protector. Her guardian. From herself. From it: the Black Lagoon. It wasn’t like he was trapped. The doors were not locked. She made no rules, issued no commandments, decreed no penalties, and exacted no punishments. Staying Inside was something he’d invented, intuited, for her sake, to keep her from falling so deep she’d tremble and explode and weep all her tears and go dry and insubstantial as the dandelion fluff that occasionally coasted Inside like tiny satellites. He’d always known that if fear took her for good, he’d be left treading water forever in the ocean of life with nothing to buoy him.

But birds usually made a different sound against the window, more sickening and soft, like a strike from those plush drumsticks used in marching bands, not the sharper bang he’d heard. In a gust of curiosity, Will had set down the fan brush he was using to texture a block of mustardy-green acrylic paint, then removed his smock and slipped out the front door as easily as entering a long-neglected wing of their house. He hadn’t actually expected catastrophe, or a bloodbath, but with little to compare to, hadn’t ruled them out either. Wordlessly she’d taught him that the Outside was built of danger, of slicing edges and crushing weights, of piercing needle-points and pummeling drop-offs, of an unrelenting potential for suffocation, electrocution, mayhem, and harm. So today a generous portion of him was left mutely astonished that, so far anyway, the Outside was nearly pleasant.

Thrilling himself with his own daring, Will moved now from the concrete out into the grass, grotesquely alive beneath his feet—a carpet made of salad that he half-expected to grip his toes and hold him fast. Luckily, his Helmet would safeguard him if he tripped or a branch dropped lethally from above. After some painfully prickly searching in the cedar bushes, he found it, the source of the bang: a husk of charred matter that resembled a tiny exploded wasp nest, smoking faintly like the humidifier his mother put in his room in the winter. The dirt was blackened around it, the air charred and sulfurous, and it occurred to Will this was some kind of bomb.

Now he glimpsed a figure dart around the side of the house, boy shaped, something heavy looped over his shoulders, and Will wondered if he’d been hurt somehow by the explosion. Will followed him around the corner, passing the strange dryer vent fuming with the startling Inside smell of fabric softener and warmed clothes, their clothes, and had just rounded the rear of his house when he toppled, a nuclear drill of pain boring between his temples, a masterpiece film of neon spindles whirling through his eyelids. Some diminished part of his mind registered a demonic shrieking, and he realized then that the noise was being squeezed from his own lungs. Desperately, he shaped the sound into an anguished plea for his mother but knew she couldn’t hear him with her Relaxation Headphones on. Amid the murk of agony he gathered the sense that something had struck his forehead and fallen to his feet. He tore open his eyelids. A purple crystal. The sun dazzled it before Will’s vision was again welded shut, this time a stickiness there. Still moaning, he bent, felt for it in the grass, and closed his hand around the rock.

“You’ll be fine,” a nearby voice said.

Will attempted to again pry open his eyes, but a stinging honey had sealed them. He stumbled forward with his hands lifted in the Outside air, baffled, sobbing, afraid to wipe his face for fear he’d make his mortal wound worse.

“Here,” the voice said, and Will sensed fabric against his face. He took it and pawed at his gluey eyes, prying them open to find a delivery boy, tucked behind the aluminum shed that Will had never entered. The boy had a green garden hose coiled around his shoulder and was about Will’s height and age, with stringy bangs that licked at eyes flitting everywhere except upon Will. His brown skin was the tint of the milky tea his mother often drank in her reading chair, balancing the cup precariously on the wooden arm—her most dangerous habit. In his hand was a target slingshot, the kind with thick rubber straps and a brace running up your forearm, a forbidden item that Will had ogled in catalogues for as long as he could remember.

“I didn’t even pull it back halfway, so you’ll live,” the delivery boy said smiling, the sudden warmth of his face momentarily soothing the ache of Will’s probable skull fracture, which he could already feel opening like a pistachio.

“You really think I’m going to live? Like, for sure?” said Will, woozy with blood loss and imminent death. “I’ve never heard anyone say that before …” Will pulled the boy’s shirt away for a moment, and more blood licked his eyes.

“For a while, anyway,” the boy said, shrugging. “But sorry, I thought you were someone else.”

“Who? The person who set that little bomb out front?” Will said, secretly wondering if the Black Lagoon could possibly be after this boy as well.

“Yeah,” the delivery boy said. “Among others.” He unshouldered the garden hose and dropped it to his feet. Will now saw that his smooth chest was festooned with a solar system of a hundred milky scars.

“Oh, are you hurt too?” Will said. “Did the bomb get you when you were delivering our new hose?”

“I’m fine,” the boy said casually before scrambling over to peek around the corner of the house like a soldier in a firefight.

Will followed him closely to examine his injuries. “Then how did you get those scars? Did the Outside do that to you?” The delivery boy turned and regarded Will as if he were speaking some cryptographic language, and Will wondered whether the infinite Outside air had tarnished his words somehow.

“What’s your name, kid?” the boy said, returning behind the shed, keeping his eyes fixed to the tree line near the creek behind Will’s house.

“Will. What’s yours?”

He paused, and Will was about to ask if he was okay again. “My name is Will too,” the boy said.

“Really?” Will said, tickled by the coincidence. “Are you hiding from someone, Will? Do you have your own Inside you can go to? If not, you can hide here. We could eat some of my mother’s bread and look at my masterpieces.”

“You live here?” the boy said, puzzled, tipping his head back toward Will’s house. “I thought this place was empty.”

Will tried not to think about his house. How disturbing it looked from the Outside, how shabby and finite. “Just me and my mother,” he said. “But this is my first time in the backyard,” he added. “I used to be afraid of going Outside, but now I’m mostly not.”

“That’s great, Will,” the delivery boy said. “Really great. But you do need to be careful out here. It can be dangerous. You should probably play it safe and go back inside and not tell anyone you saw me? Like your mom or anything?”

“Oh, I’m definitely not telling my mom about this,” said Will, pointing at his forehead. “I only came out because I heard that bang out front.” It was then he realized that the garden hose at the boy’s feet was old and worn. “But you weren’t delivering that hose, were you?” Will whispered conspiratorially, approaching him to lean in close. “That was already ours, right?”

“Anyway, it was good talking to you,” the boy said in a businesslike voice, jamming his slingshot into his shoelace belt and striding out into the backyard, exposing a lithe back just as baroquely scarred as his front. “I’d better get—”

“—It’s okay, you can have it!” Will interrupted, too afraid to follow him out into all that grass, astonished by how bravely he swam through the ocean of the Outside. “The guy who does our garden usually brings his own anyway. I’ll just order another one.”

“That’s real good of you, Will,” the boy said, returning to tentatively pick up the hose. His eyes drifted up to Will’s Helmet. “Too bad I didn’t aim a little higher,” he said with an odd smirk. “But you can keep my shirt. And maybe I’ll see you around.”