Colonel Phil Greenlaw believed he had outgrown the nighttime fears of his childhood—right up until the day he became a father himself.

As a small boy, he had imagined endless horrors in the darkness of his bedroom. When the branches of the ash tree just outside the window scraped against the glass on stormy nights, he imagined the fingers of something dead and hungry. When the house creaked all around him, he recognized it as ghosts or intruders or rats in the walls. His parents indulged him by moving his bed twice—first against the wall because he felt too vulnerable, and then away from the wall because he was certain there were spiders hiding in the space between the bed and the wallpaper.

In time, of course, such fears had come to seem foolish. As a teenager he had thought of sleep only as a last resort, and bed as a place to collapse when exhaustion overwhelmed him. If, as an adult, he had nights when sleep didn’t come so easily and the shadows of his bedroom took on a familiar ominous quality, he would remind himself that he wasn’t a child anymore. He was a soldier.

Tonight he lay half-awake, listening to the sounds of his home and his sleeping family, wondering what had roused him. He turned onto his side and settled deeper into his pillow, soothed by the soft snoring of his wife, Carla, beside him. Drifting in the fog around the outskirts of sleep, he let the nighttime noises seep in. The hum of the cable box seemed strangely loud with the lights off. The air conditioner whispered through the vents. The little stone fountain Carla had bought at some New Age shop out on Sanibel Island burbled gently.

But sleep wasn’t coming.

Phil opened his eyes again, brow furrowed with consternation. Had he actually heard something out of place? Ever since he and Carla had brought the twins home for the first time, he had not slept properly. Neil and Michael were adopted, but they had still been infants when they became Phil and Carla’s children. Too many nights he had woken and wandered the house, checking to see if they were still breathing, or just standing in the half-open doorway of their room to watch them sleep. As the months passed, he had begun to relax a little.

So what was it tonight?

He slid nearer to Carla and put one hand on the curve of her hip. Sometimes just touching her helped him to get back to sleep. It was not something an Air Force colonel would ever have admitted to his colleagues, but he loved her fiercely. Bringing the boys home—seeing the joy in her eyes at finally becoming a mother—had been even more rewarding than his own happiness at becoming a father.

Inhale, exhale, let out the weird tension, and close your eyes against the shapes made by the shadows in the dark. Go to sleep.

But the tiniest of squeaks made him open his eyes again. Not a mouse. This had been a strangely metallic squeak. Another sound followed—a shifting of weight on wood, the creak of a presence that did not belong. A cold fear trickled through his heart and he propped himself up in bed, listening. It could be nothing … was probably nothing. Just the house, the wind, a shift in air pressure, the air conditioner, a towel finally dropping off a doorknob from which it had slipped by infinitesimal fractions over the course of hours.

He had climbed out of bed and checked on the boys dozens of times, had gone downstairs to investigate strange sounds hundreds of times before he and Carla had even had children. And he always made the rounds before going to bed, checking locks and shutting off lights before he carried two glasses of water upstairs—one for him and one for Carla.

But that peculiar metallic squeak lingered in his mind. And though he heard nothing more to alarm him, he could not erase it.

Then he heard a muffled voice, probably a moan, and he understood—Neil must be having another nightmare. The boy sometimes had bad dreams and would talk in his sleep.

Phil slipped out of bed, careful not to uncover Carla. The air-conditioning made her too chilly to sleep without the covers. He took a sip of water from the glass on his nightstand. Even with the A/C running, the ice had long since melted. The clock on the cable box glowed the time, 2:12 a.m. He waited half a minute but heard nothing more. Half-asleep, he scratched his head and thought about lying down again, but he had already committed to investigating the noise, and now that he’d sat up he felt a dull fullness in his bladder that urged him on.

Standing, he rubbed at the sleep in his eyes and shuffled toward the door. He would just peek into the twins’ room. If he woke them now, especially if Neil had been having a bad dream, they’d want him to stay and he would end up asleep on the carpet between their beds. Carla would have to get up when his alarm went off, and he’d be stiff as hell from hours on the floor.

Gingerly, he drew open his bedroom door and stepped into the hall.

“Phil?” his wife said sleepily. “What are you doing?”

He turned and glanced back into the room. Her brown hair looked black in the dark, and it spilled across her face in a lovely mess.

“I thought I heard something,” he said.

A drowsy, playful smile touched her lips. “Nudge me when you come back to bed.”

Phil grinned, his anxiety vanishing. He had learned early in their relationship that Carla enjoyed the soft, tangled, dreamy intimacy of late-night sex. Sometimes she stroked or nibbled or licked him awake in the small hours of the morning.

“Guess I’m not the only one who’s restless tonight,” he said.

She arched an eyebrow. “Are you complaining, Colonel?”

“Not even a little.”

“Then hurry back.”

Brain buzzing with the anticipation of sex, he turned away, toward the boys’ room. An unfamiliar shadow loomed in the hall, half-silhouetted in the twins’ open doorway, and his smile faded. For the tiniest moment, Phil hesitated, presuming this was yet another in a lifetime of illusory nighttime shadows, but as he blinked, the shadow lunged at him.

His training kicked in along with his fear, but not fast enough. That tiny hesitation cost him his life. His skull slammed against the soft green paint of the corridor wall and powerful hands gripped his throat. He heard Carla screaming in the bedroom, heard her struggle to disentangle herself from the sheets as the footfalls of a second shadow rushed to attack her.

From the boys’ bedroom, however, he heard only silence.