SGHS was the town’s original school. It boasted several vintage buildings and a decrepitly grand auditorium surrounding a faded brick plaza, a core around which more modern buildings—if you could by any stretch of the imagination call the 1970s modern—had sprouted. There was the open-classroomed, two-story windowless monolith of the B building, along with rows of “temporary” trailers that constituted a significant portion of the school since the late sixties.

  Anna made her way through the empty quad in the pre-dawn dark. The buildings were looming shadows around her, no lights on yet. Zero period, six a.m., existed so that seniors could get in their class hours for graduation while still being able to leave school early enough to work. Anna was cramming in all the credits she could in the desperate hope of graduating early. After fourth period she left school to get downtown to her job at the Inland Center Gap—anything to avoid going home.

  The long shining corridor of the A Building was dim and deserted, only one lit classroom at the far end of the hall. Anna’s zero period, Problems of Democracy, was a graduation requirement, and unlike most other classes in the school, which were tracked according to student test scores, POD was taught on only one level, which meant classes were mixed in a way they simply were not for others.

  POD was technically a senior course, and Anna was a junior, but the class was easily the least challenging she’d ever taken, possibly in her life. The scattered students in the large, militantly undecorated room were the absolute dregs of the school. The dumbest of the football team—linebacks or whatever the biggest ones were called, a few slutty girls who seemed physically incapable of picking up their feet and consequently shuffled noisily when they walked, and some sweet-faced Latino boys who no one seemed to have noticed didn’t speak more than ten words of English between them. A good three-quarters of the class was sleeping, heads down on their crossed arms on their desks. This included the teacher: pale, doughy Mr. Doyle. It all looked like the courtyard scene from Sleeping Beauty after the fairies had put the whole castle in suspended animation while Beauty awaited the awakening kiss of the Prince.

  Despite herself, Anna stole a glance around the room for Tyler, the closest thing SGHS had to a prince—the only thing that kept Anna coming to POD at this ungodly hour. No sign of him.

  The only other moving thing in the room was Carrie Thornton, the school’s most unfortunate dwarf. “Little person” was the PC phrase, but Carrie was undeniably a dwarf—three foot ten, a hundred and fifty pounds, with a froglike face, lashless eyes. She wasn’t retarded, exactly, but there was something not right about her mind, either. The jocks were merciless, pretending to be her friend and then mimicking her duck walk and turtle blink behind her back—barely behind her back. Carrie surely knew she was being mocked, but waddled after them anyway, trying to keep up with the young gods on her stumpy legs.

  It was the height of teenage cruelty: Darren Elwes, captain of the water polo team, school sociopath, the ringleader, ostentatiously flirting with her, going on and on and on obscenely about taking her out to the drive-in, about what base they’d gotten to the night before, about jerking off to the memory afterward. Disgusting. Unbearably, it seemed to excite Carrie. She’d stagger away in a flushed stupor as Darren mugged behind her in panting imitation of her froggy face, the lettermen and any stray cheerleaders laughing uproariously.

  Except for Tyler, who never laughed, but sat beside them, a million miles away, as if on another planet. Never entirely present, always at the edge of the group, dreamily aloof or (Anna wasn’t stupid) drugged. So different from Them. But at the lunch bell or the last bell he would get into Darren’s car or Darren into his, and they drove off together to their childhood homes, three houses apart from each other.

  Anna quickly took a seat between two sleeping students to avoid engaging in conversation with Carrie, whom she pitied, but not enough to endure her desperate, disjointed chatter.

  The bell rang (such an assault at this hour) and Mr. Doyle blinked awake at his desk. The class slept on. Doyle licked his lips, growled, “Get out pencils for a quiz. No books.”

  Anna fumbled in her backpack—and then felt someone looking at her, the back of her neck was hot.

  She turned to the row of tables behind her.

  Tyler Marsh sat behind her, alone at one of the two-person desks as if he’d materialized from—

  A dream … the dream … .

  He was looking straight at her, his long dark hair falling around his face. Their eyes locked in an electric moment.

  It all came flooding back to her, the smoke-filled halls, the ominous dark shape darting in the classroom behind her, too quick to be human—two heads.

  And Tyler, at the foot of the stairs, looking up.

  She was there, then here—then both at once, realities layered on top of each other.

  Tyler locked in to Anna’s gaze from across the room. Chills ran up her back as he slowly nodded.

  What? What?

  “I was there,” he said without speaking.

  She caught her breath, looking into those eyes.

  And then Doyle stepped in front of her, and slapped a paper down, beginning the test.

  At the sound of the bell Anna raced to catch up with Tyler, running into a chair and bruising her shin in her hurry to escape the room. But outside POD the halls stretched out endlessly, filled with nothing but the shuffling corpses of her other classmates. He’d disappeared.

  Daylight had brought the Santa Anas gale force, gusting and crackling through the palms.

  Anna walked through the quad, prime real estate for jocks, cheerleaders and other socies. Wannabes hovered hopefully on the periphery, always looking for an opening or whatever miracle it would take to join the inner circle. She saw Tyler as soon as she hit the bricks of the inner quad. He was with the usual gang, seated around the central planter, Darren never far from his side.

  It was a childhood connection, that much Anna understood: the two of them growing up on the same block of Valencia, the broad main street of town. This was prime real estate for society parents, facing the golf course, a short drunk walk to or from the Country Club. Kids growing up with golf and Junior League and SUVs and iPhones and iMacs and an inbred sense of entitlement. Big fish in a small, small pond.

  Tyler was in his place on the south side of the planter, as always at the edges of the group, smiling slightly, never quite participating in Darren’s hijinks. Today, some sort of air guitar recounting of a concert, with lots of tongue involved.

  Anna drifted more slowly, willing Tyler to look at her. He had spoken in her head, as clearly as if he had been on the phone. Could she speak in his?

  Try it, why not? Nothing to lose, everything, everything to win.

  She breathed in, and said it in her head.

  Tyler.

  She kept her eyes on him, every cell within her concentrating, focused on one thought.

  Tyler.

  She saw him blink, frown, look up and around him. She was barely moving, barely breathing.

  Then Darren cavorted closer, shoved him. Tyler struck out and hit him so quickly even Darren looked surprised. Darren burst into manic laughter, echoed by everyone around them.

  “You are one crazy motherfucker,” Darren crowed, feinting back at Tyler.

  Tyler did not once look at Anna. She dropped her eyes and walked quickly on, her face a mask.

  So maybe it hadn’t happened at all. Maybe none of it had.

  Maybe she was crazy. As crazy as her father.

  The morning dragged on; her hated Algebra II class, Mr. Maitland with his too-tight shorts and crawling eyes. Then third period Chem, the dark, windowless second-floor lab soporific as always, Litwack spacing out behind his desk, mug of coffee well laced with vodka.

  As the class practiced titration, Anna could see more than the assignment bubbling at a back table: Darren and a couple of other water polo guys were huddling too industriously over a beaker. Darren suddenly looked up, straight across the room at Anna. His lip curled and his eyes went colder than their usual glacial blue. The menace in his face made Anna look quickly down at her notes and try to disappear into them.

  It was not two minutes later that the beaker exploded. Blue smoke spread instantly through the room, noxious, suffocating. Startled back to semi-sobriety, Litwack barked orders at the hapless TAs and ordered the students out of the room “In an orderly fashion.”

  In the halls, chaos. Alarms shrieked as students poured from the science, math and computer labs, pushing and screaming. It was instantly clear that the school population far exceeded the evacuation capacity of the building. A wall-to-wall river of bodies undulated in excruciating slow motion toward the main staircase in the front of the building. Anna turned instinctively toward the side emergency stairs. A clutch of students was squeezed against the doors, voices rising in a spiraling frenzy. From where she was, Anna could see that some idiot had wrapped a bike chain around the bars of the emergency exit.

  This was planned. It was a setup.

  The students twisted, fighting to turn where they stood. Teachers shouted over the chaos, adding to the madness.

  The river of students surged forward. The sound of crashing glass, blue smoke, shrilling alarms surrounded Anna as she was carried through the corridor on a wave of déjà vu.

  In the pushing, shoving horde, someone fell into step with her, and she looked up to see long silky dark hair, deep wary eyes, clear skin in perfect profile. Tyler. He put a hand to her elbow and held her, keeping her beside him in the jostling crowd. They moved in tandem, saying nothing. She was dizzy with the reality of him.

  There was a logjam at the stairs, an ocean of students. Anna and Tyler inched forward.

  “Good thing it’s not for real,” Tyler said with casual cynicism.

  “It was real last night,” she said. For a moment she thought he would not speak. Then—

  “It was something.”

  Their voices were soft in the din of wired chattering and occasional shrieks. She could hear him perfectly. She looked up, into his eyes, as if she had every right to do it. They were green, like the sea. “We had the same dream,” she said, in wonder.

  He shook his head slowly. “I don’t dream.”

  “Everybody dreams,” she said automatically. “We’d all be completely psychotic if we didn’t.” She’d read it somewhere, or maybe it was one of those classroom movies that have a strange way of sticking, random facts popping up when you least expect it.

  “I don’t dream,” he repeated. “You were in my bed last night.”

  She was flooded with heat and confusion until she realized he’d said “head” not “bed.”

  The smoke was thicker—people all around them were coughing, crying.

  “The smoke was in the beginning,” she said, the dream flashing with crystal clarity in her mind. “There were people dead.”

  He looked down at her a long time, then nodded without speaking.

  “There was someone. Someone dark and fast in the halls. Someone … with two heads.” She’d actually said it aloud. He didn’t react. “Did you see?” she asked urgently. She couldn’t believe she was talking to him like this. They had never spoken before.

  He frowned slightly. “No.” There was not a trace of skepticism in his voice.

  The crowd moved them closer to the stairs. If someone tripped, they would be trampled.

  Anna glanced toward Mr. Brooke’s classroom to the left of the stairs, remembered the legs sticking out from under the desk, and shivered.

  “People are going to die,” she said softly.

  Algebra II. Maitland, with his bristly red beard and red mouth, tennis shorts with their insinuating bulge, rubbing past her in the aisle as he lectured, standing with his crotch at her eye level as he paused to “check her work.”

  They were studying probability, and Anna vaguely realized that there was something potentially magnificent about it, something philosophical and profound. But Maitland’s leering and covert groping made it impossible for her to concentrate—her mind just shut down. She stared down at her textbook, trying to block him out as he cruised the aisles. She copied a definition onto her worksheet, a list of probability terms:

  Sample Space: The set of all possible outcomes.

  She sat up straighter, with a thrill of significance. Right there, for example. Sample Space. Wasn’t that where she and Tyler were right now, in a set of all possible outcomes? She scooted up farther on her seat and flipped pages to find the definition of the next phrase.

  Probability: The likelibood of the occurrence of an event.

  Again, she felt a chill. And that’s what they were struggling with, the likelihood of the occurrence of an event. An event … Her mind skittered away from the dream memory and she hurried on to:

  Conditional Probability: A probability that is compiled based on the assumption that some event has already occurred.

  Some event that had already occurred. The fire alarm in their dream and then in reality … .

  The next term on the list made her heart leap.

  Impossible Event: For any event A, O≤P(A)≤1 P (impossible event) = 0

  That was it. That’s what she needed to know. Her eyes raced over the chapter text looking for the explanation as if—as if—

  As if lives depended on it.

  She looked down at the page and the line suddenly jumped out at her.

  An impossible event has zero probability of occurring.

  She stared down at the page bleakly. Well, that was self-evident, wasn’t it? But if an impossible event had zero probability of occurring, then probability had nothing to do with what was happening, because it was all impossible—

  A shadow fell on the page. Maitland was standing above her, his eyes glittering down. Anna froze as his hand moved down to his crotch and he began to stroke himself.

  She stared up, hating him—

  And his head exploded. Blood and brain drenched Anna’s dress and Doc Martens. She gasped, recoiled from the coppery stink and slime of blood.

  Headless, brain stem exposed, Maitland turned in slow motion as if to confront his killer, then crumpled to the floor.

  Anna forced the terror down, forced herself to focus, to think. The dream … she was in the dream again …

  She stood from her desk, awash in red. She was alone in the classroom, Maitland’s body at her feet.

  She looked around. No, not alone. There were others, slumped at desks, holes in their heads and chests.

  Smoke and blood were everywhere.

  In the hall behind her, the shadow skittered. Fast, so fast …

  Anna ducked down beneath the desk, and crouched there, her ears filled with the thudding of her own heart and the faraway pulse of the alarms. She peered through the smoke toward the hall. Nothing moving. She took a breath and crawled along the edge of the fiberglass dividing curtain to the wall-less back of the Algebra classroom.

  More smoke in the corridor and more fallen students. She felt movement, turned her head to see a figure down the hallway, almost obscured by the smoke. She caught a glimpse of legs in jeans and snakeskin boots, a rifle at thigh level and the shadow on the wall, its two heads bobbing.

  A dull boom rocked the building, jolting Anna onto her hands and knees.

  Around her there was screaming and screaming and screaming, and then the crackle of flames. The smoke surrounded her, hot and intimate and oppressive.

  She crawled along the wall, eyes streaming.

  There was another body in front of her, crumpled, not moving. Dark silky hair pooled on the carpet around his head. And blood, so much blood.

  No, God, oh no, no …

  Her heart was in her mouth as she crawled to Tyler, oblivious of the shadow creature. He was still and pale. She lifted his head, cradling him in her arms. Blood was sticky on her hands, running through her fingers. The back of his head was soft, like melted Jell-O. Her pulse spiked as she felt the ooze.

  He opened his eyes, found her gaze. She saw recognition … longing … relief … he shuddered, and she held him harder.

  “Help me,” he whispered.

  Anna’s eyes swam with tears. His hand moved beside her leg, touched her fingers and picked up her hand. He raised her hand to his mouth, she felt his lips brush her palm—

  Behind them, the two-headed shadow loomed on the wall … .

  “We have to stop it.”

  She spoke with utter calm. In her head was her own screaming from the dream.

  They were sitting on the stairs at the side of the auditorium, privacy from the traffic of the quad, its cliques and gossip. They sat close, legs touching, as if they had known each other forever. As if, as if … .

  “What is ‘It’?” Tyler said. His voice was mocking but his eyes were not. The noon sun blazed down, shimmering off the concrete.

  “You know,” she said, and still hesitated. “Like Columbine.” It felt odd to say it aloud. Had she ever said the word before?

  It can’t happen here it can’t happen here it can’t happen here

  “What do you suggest we do?” he said reasonably. And there was the rub, wasn’t it?

  “Tell someone.” Her voice grated, as if she were irritated. As if irritated could begin to describe her feelings.

  “Tell who? Our parents?” There were layers of complexity in the way he said the word.

  “No,” Anna said quickly, and he smiled without amusement.

  “No,” he agreed. A vision of her father, stumbling drunk and raving, flashed in Anna’s mind. Tyler flinched, as if he saw. Their eyes met and she knew they had much more in common than she had ever guessed.

  Then he looked away, and shrugged. “What’s there to tell, anyway? ‘We had a dream … .’”

  “It was more than a dream. You know it. You know it. People don’t dream the same thing.”