21.

WHEN IT WAS DONE, he crawled to the bed and pulled out the broken slat. A little long for a crutch-he had to hold the board at a difficult angle-but it would have to do. He hobbled to the other bedroom, where he found men's clothing: a pair of jeans, a plaid shirt, a hand-knit sweater, and a leather jacket with the name of the owner's bowling team, The Urbana Pinheads, emblazoned on the back. The fabric scraped and rubbed against his raw skin, making every movement a study in pain. Then he shuffled into the living room, where he found Grace's rucksack and rifle. He threw both over his shoulder.

Hours later, resting in the nestlike mangle of metal in the middle of an eight-car pileup on Highway 68, he opened the sack to take inventory and found dozens of plastic baggies labeled with black marker, each bag containing clippings of human hair. At first he was puzzled. Whose hair was this and why was it in baggies, each neatly marked with dates? Then he understood: Grace was taking trophies from her kills.

Where the body went, the mind followed.

He fashioned a splint for his ankle from two pieces of broken metal and the rest of the bandage roll. He drank a few sips of water. His body ached for sleep, but he would not sleep again until he kept his promise. He lifted his face to the pinpricks of pure light fixed above him in the limitless dark. Don't I always find you?

The headlamp of the car beside him exploded in a shower of pulverized glass and plastic. He dove beneath the nearest vehicle, dragging the rifle behind him.

Grace. It had to be. Grace was alive.

He left too quickly. He assumed too much, hoped too much. And now he was trapped, pinned down with no way out, and Evan realized in that moment how promises can be kept in the most unexpected of ways: He'd found Cassie by becoming her.

Wounded, trapped beneath a car, unable to run, unable to rise, at the mercy of a faceless, merciless hunter, a Silencer engineered to snuff out the human noise.

22.

HE MET-found would be more accurate-Grace the summer they both turned sixteen, at the Hamilton County Fair. Evan was standing outside the exotic petting zoo tent with his little sister, Val, who had been demanding to see the white tiger since they arrived early that morning. It was August. The line was long. Val was tired and grouchy and sticky with sweat. He'd put her off. He didn't like to see animals in captivity. When he looked into their eyes, something in their eyes looked back at him.

He found Grace first, standing beside the funnel cake trailer, a dripping wedge of watermelon in her hand. Blond hair that fell to the middle of her back, cool, nearly arctic features, especially the ice-blue eyes, and the cynical turn of her mouth, glistening with juice. She turned toward him and he quickly looked away, to the face of his baby sister, who would be dead in less than two years. A fact he carried within him, locked away in a different kind of hidden room. Sometimes it was hard to shake-the knowledge that every face he saw was the face of a corpse-to-be. His world was peopled with living ghosts.

"What?" Val asked.

He shook his head. Nothing. He took a deep breath and glanced toward the trailer again. The tall blond girl was gone.

Inside the tent, behind a steel mesh fence, the white tiger panted in the heat. Small children crowded in front. Behind them, cameras and smartphones clicked. The tiger remained regally indifferent to the attention.

"Beautiful," a husky voice murmured in Evan's ear. He did not turn. He knew, without looking, it was the girl with the long blond hair and lips that glistened with watermelon juice. The exhibit was packed; her bare arm brushed against his.

"And sad," Evan said.

"No," Grace said. "He could tear through that fence in two seconds. Rip off a kid's face in three. He's choosing to be there. That's the beautiful thing."

He looked at her. Her eyes were even more startling up close. They bored into his, and in a knee-weakening instant, he knew the entity hiding inside Grace's body.

"We should talk," Grace whispered.

23.

AT DUSK, the lights of the Ferris wheel were switched on and the tinny music was turned up and the crowd swelled along the midway, cutoff shorts and flip-flops and the smell of coconut-scented sunscreen and the waddle of big-bellied men in John Deere caps with deeply callused hands and wallets attached to belt loops bulging in back pockets. He handed Val off to their mother, then headed for the Ferris wheel to wait nervously for Grace. She materialized out of the crowd, holding a large stuffed animal: a white Bengal tiger, plastic bright blue eyes only slightly darker than hers.

"I'm Evan," he said.

"I'm Grace."

They watched the giant wheel turn against the purple sky.

"Do you think we'll miss it when it's gone?" he asked.

"I won't." Her nose crinkled. "The smell of them is horrible. I can't get used to it."

"You're the first I've met since . . ."

She nodded. "Me too. Do you think it's an accident?"

"No."

"I wasn't coming today, but this morning when I woke up, there was this little voice. Go. Did you hear it?"

He nodded. "Yes."

"Good." She sounded relieved. "For three years I've been wondering if I'm crazy."

"You're not."

"You don't wonder?"

"Not anymore."

She smiled archly. "Do you want to go for a walk?"

They wandered over to the deserted show grounds and sat on the bleachers. The first stars appeared. The night was warm, the air moist. Grace wore a pair of shorts and a sleeveless white blouse with a lace collar. Sitting close to her, Evan could smell licorice.

"This is it," he said, nodding at the empty corral with its mangled floor of sawdust and manure.

"What?"

"The future."

She laughed as if he'd made a joke. "The world ends. The world ends and the world begins again. It's always been that way."

"You're never afraid of what's coming? Never?"

"Never." Hugging the stuffed tiger in her lap. Her eyes seemed to take on the color of whatever she looked at. Now she was looking up at the darkening sky, and her eyes were a bottomless black.

They spoke for a few minutes in their native language, but it was difficult and they gave up quickly. Too many words were unpronounceable. He noticed that she was much calmer afterward, and he realized it wasn't the future that frightened her; it was the past, the fact that she feared the entity inside her body was a figment of a young human girl's shattered mind. Meeting Evan validated her existence.

"You're not alone," he told her. He looked down and discovered her hand in his. One hand for him, the other for the tiger.

"That's been the worst part," she agreed. "Feeling as if you're the only person in the universe. That the whole thing is here," touching her chest, "and nowhere else."

Years later, he would read something quite similar in the diary of another sixteen-year-old girl, the one he found and lost, found, then lost again: Sometimes I think I might be the last human on Earth.

24.

THE CAR'S UNDERCARRIAGE against his back. The cold asphalt against his cheek. The useless rifle clutched in his hand. He was trapped.

Grace had several options. He had two.

No. If there was any hope of keeping his promise, he had just one: Cassie's choice.

She had made a promise, too. A hopeless, suicidal promise to the one person on Earth who still mattered to her-mattered to her more than her own life. She stood up that day to face the faceless hunter because her death was nothing compared to the death of that promise. If there was any hope left, it lay in love's hopeless promises.

He crawled forward, past the front bumper, into the open air, and then, like Cassie Sullivan, Evan Walker stood up.

He tensed, waiting for the finishing round. When Cassie stood up that cloudless autumn afternoon, her Silencer had run. He did not think Grace would run. Grace would finish what she began.

But no finish came. No silencing bullet, connecting Grace to him as if by a silver cord. He knew she was there. Knew she could see him standing crookedly in front of the car. And he realized there was no escaping the past, no dodging inevitable consequences: Cassie's terror, her uncertainty and pain, they belonged to him now.

Overhead, the stars. Straight ahead, the road that shone in the stars' light. The tight grip of the freezing air and the medicinal smell of the ointment Grace had spread over his burns. Your heart is beating very fast.

She's not going to kill you, he told himself. Not the goal. If killing you was the goal, she wouldn't have missed that shot.

There could be only one answer: Grace intended to follow him. He was a riddle to her and following him was the way to solve the riddle. He had escaped the trap only to sink deeper into the pit. Keeping his promise now was not being faithful; it was an act of betrayal.

He couldn't outrun her, not with the bad ankle. He couldn't reason with her-he could barely articulate his own reasons anymore. He could wait her out. Stay here, do nothing . . . and risk Cassie being discovered by soldiers of the 5th Wave or abandoning the hotel before his stalemate with Grace ended. He could force a confrontation, but he'd failed once and the odds were he would again. He was too weak, too hurt. He needed time to heal and there was no time.

He leaned against the hood of the car and looked up at the star-encrusted sky, undimmed by human lights, scrubbed clean of contaminants, and these the same stars that shone on the world before humankind walked upon it. For billions of years, these same stars, and what was time to them?

"Mayfly," Evan whispered. "Mayfly."

He shouldered the rifle and wormed his way through the pileup back to the backpack of supplies, which he threw over the other shoulder. Tucked the makeshift crutch beneath his arm. The going would be slow, painfully slow, but he would force Grace to choose between letting him go and following him, deserting her assigned territory at the moment when desertion could mean a serious setback in the carefully constructed timetable. He would swing north of the hotel-north toward the nearest base. North where the enemy had fled and retrenched and waited for spring to launch the final, finishing assault.

That's where hope lay-where all hope had been from the beginning-on the shoulders of the brainwashed child-soldiers of the 5th Wave.

25.

LATER THAT EVENING on the day they met, Evan and Grace walked along the midway beneath the lights that beat back the dark, weaving their way through the crowd, past the ring toss and balloon dart game and basketball free throw. Music blared from speakers mounted on the light poles, and bubbling beneath the music was the sound of a thousand conversations, like an undercurrent, and the flow of the crowd was like a river, too, eddying and swirling, swift here, languid there. Tall and lissome and striking in their good looks, Evan and Grace drew attention from the passersby, which made him uncomfortable. He never liked crowds, preferring the solitude of the woods and the fields of the family farm, an inclination that would serve him well when the time of cleansing arrived.

Time. Above them, the stars turned like the points of light on the Ferris wheel that loomed above the fairgrounds, though too slowly for the human eye to register, the hands of the universal clock that was winding down, that had been winding down from the beginning, and the faces that passed marking the time, like the stars themselves, prisoners to it. Evan and Grace were not. They had conquered the unconquerable, denied the undeniable. The last star would die, the universe itself would pass away, but they would go on and on.

"What are you thinking?" she asked.

"'My spirit will not contend with humans forever, for they are mortal.'"

"What?" She was smiling.

"It's from the Bible."

She shifted the stuffed tiger to her other hand so she could take his. "Don't be morbid. It's a beautiful night and we won't see each other again until it's over. Your problem is you don't know how to live in the moment."

She tugged him from the main concourse into the shadows between two tents, where she kissed him, pressing her body tightly against his, and something opened inside him. She entered into him and the terrible loneliness he'd felt since his awakening eased.

Grace pulled away. Her cheeks were flushed, her eyes burning with a pale fire. "I think about it sometimes. The first kill. What it will be like."

He nodded. "I think about it, too. Mostly, though, I think about the last one."

26.