Evie took deep, measured breaths, as if she were about to sit down for a final exam. She knew that every time she had undertaken some mission since the invasion, she had put herself at risk. Surveilling Brume-sur-Mer, accessing Salome’s interface, blowing up the drill site—all of these things had been dangerous.

But never before had she run right into the middle of a Covenant-occupied zone.

This is so stupid, she told herself.

But she knew she was going to do it anyway.

They were waiting at the base of the hill, in a pile of dusty debris. Owen crouched between Evie and Victor, with Dorian in front and Saskia to the rear. Evie felt safe here, in her little nest of rubble. She knew she was about to throw all of that safety away.

“Position?” Owen murmured softly into his comm. Evie couldn’t hear the answer, but it made Owen say, “Good. Yellow Squad: position?”

Evie listened to this litany as she breathed, trying to imagine herself successfully racing across the open field and diving into the structure. They got one shot to do this. One shot to prove her and Victor’s theories.

“Ready,” Owen said, still speaking into his comm.

Evie’s chest constricted. Light from the Covenant encampment spilled through the transparent hunks of melted detritus currently keeping her hidden.

“Like we talked about,” he murmured. “Green Squad, get ready—”

Evie twisted her fingers in the fabric of her jacket, wanting something that could ground her.

“Initiate,” Owen said, and immediately there was the rat tat tat of UNSC military rifles. The air flooded with surprised shouts of anger in at least three different Covenant dialects. Evie resisted the urge to stick her head out from the garbage pile to see what was happening in the war zone. Instead she listened: to the whine of a Banshee engine, no doubt circling overhead for the shooter; to the pulse of plasma weapons and the rattle of human rifles.

“Blue Squad,” Owen said. “Initiate.”

Evie pressed one hand to Dorian’s back. He twisted around, debris shifting around him.

“You ready?” she whispered.

“I’m doing this for you,” he whispered, and something tightened in her chest.

“Green Squad,” Owen said.

Dorian nodded at her, then glanced at Owen, who gave him the go-ahead. He slipped out of the debris pile. Evie still couldn’t believe that he’d volunteered to scout out the situation.

“Initiate,” Owen said.

The sounds of war rattled around them. Gunfire, plasma cannons, the eerie sound of Banshees: All of it sent goose bumps crawling over Evie’s skin. She glanced over at Victor; he was staring straight ahead, his expression fierce and determined.

The debris rattled; Dorian stuck his head through.

“About half the Elites are still there,” he said. “The Prophet guy is gone, though, along with his bodyguards.”

“Makes sense,” Owen said. “They’d protect him at any cost.”

“It looks like they’ve sent the ground troops to suss out our people.” Dorian leaned back on his heels. “So it’s better, but not great.”

“It’s what we’ve got,” Owen said. “Lead the way.”

Dorian nodded, but he was looking at Evie. She gave him a smile she hoped was brave.

He slipped out through the debris, and the rest of them followed, sliding into the smoke and noise of the open air. A maze of fallen chunks of buildings separated them from the excavation site, illuminated by the blasts of plasma fire.

Dorian gestured, leading them forward. The smoke and dust choked at Evie’s lungs, and she squeezed the grip of her rifle so hard her fingers ached. Seven meters to get to the dig site. Without being seen.

Dorian stopped at the edge of the zone, before all the debris got flattened out. He and Owen traded places. Despite the cold air, Dorian’s face was gleaming with sweat.

“It’s wild out there,” he said.

Evie still couldn’t see, but the constant rattle of the gunfire exchange seemed to bleed together into one massive noise, a vibration echoing through the hills.

Owen looked back at them, his visor reflecting the light of the battle.

“I’m going to lay down cover fire,” he said. “There’s a clear space between us and the structure—the Elites have fanned out to deal with our snipers.” He paused. “Evie, you ready for the artifact?”

She took a deep breath. The artifact. The key component of their plan. She only hoped she could count on it to do what it had done before.

“I’m ready.” She swung her rifle back around on its strap.

Owen handed the artifact to her. It wasn’t vibrating yet, but the light inside danced wildly, almost to the rhythm of the gunfire.

“Focus on the goal,” Owen said. “And look out for each other.”

And before they could respond, he was on his feet, striding into the battle, firing his rifle.

There was a pause, a half second of hesitation. Then Evie darted forward, cradling the artifact to her chest. She didn’t look back to see if the others followed; she only did as Owen told her, and kept her focus on the goal. It was easy, since she was running toward a hole in the ground, the only spot of darkness in the entire vista laid out in front of her. Plasma fire shot around her, lighting up the sky. The artifact began rattling against her chest. Owen was right; the Elites weren’t ringed as tightly around the structure, but they were still there, firing their powerful stationary turrets up into the hills.

And then one of them was turning, its mandibled face twisting toward her, followed by the muzzle of its weapon. Panic coursed through her; she couldn’t drop the artifact, and so she couldn’t get to her gun. Why had she run forward without checking if the others were with her? What if she was out here alone, racing toward this monstrous soldier, its weapon about to fire—

And then Saskia dove in front of her, firing off her rifle. The Elite stumbled backward, Saskia’s bullets lighting up the shielding on its armor. “Keep going!” Saskia screamed. “I’ve got this!”

Evie forced her gaze away from the Elite and pressed on. The vibrations from the artifact ran up her arms, making her shoulders ache. A little closer—

A shout in an alien tongue; the Elites were circling back. At least three of them, moving toward the entrance of the structure.

The artifact yanked Evie’s arms forward.

“Now!” she screamed, praying the others would hear her.

And they did. She felt a hand on her ankle, an arm around her waist, another on her arm.

The Elites lifted their guns in unison.

And Evie’s feet lifted off the ground.

She didn’t move as fast as she had the night before, not with all the extra weight of her friends. But her theory about the artifact was correct; it wanted to be at the structure. And she felt it calibrate in her hands, some shift in the vibrations, and then, in a blink, she and the others barreled straight through the formation of Elites, plunging down into the dark of the dig site. Dirt billowed up around them. Someone was screaming.

The entrance to the structure rose up in front of them, a carved stone leviathan of sloping angles and straight arches. Evie squeezed her eyes shut as they flew across the threshold—hadn’t there been an energy shield over the door?—and then she dropped the artifact and landed hard on a cold stone floor, her breath knocked out of her body, a warm weight resting on top of her.

She blinked, groaned. Her arm muscles burned.

She heard a slap of flesh against stone and a string of curses.

“I can’t believe that worked,” Dorian said, breathless. He was sprawled out next to Evie on the ground. “You okay?”

“I’ve been better.” She moved to push herself up, but her arms trembled beneath the weight of her body. Hands gripped her hips: Saskia, pulling her up to standing.

“Thanks,” Evie said, rubbing her arms. She blinked, trying to take in her surroundings. The structure was dark. The only light came from the artifact, which lay about a meter away, its light pulsing softly.

“Were we followed?” Dorian said. “Those Elites were right behind—”

“No,” Owen’s voice boomed and echoed in the small space. “And it looks like they won’t be joining us. Certain Forerunner technology only responds to humans … looks like this structure follows those same rules. The energy shield over the door opened to admit us, and then closed behind us.”

Evie turned around, still trying to rub the soreness out of her arms. She wanted to ask Owen more about the Forerunner technology he’d met in the field, but they had a job to do. And he probably couldn’t tell her much anyway.

Owen ducked through the threshold and then straightened; as small as the space seemed, the ceiling was vaulted up high. Evie tilted her head back, but she could only see darkness.

“Even so,” Owen continued, “we’re going to want to do this as fast as possible. Let’s not push our luck here.”

Evie took a deep breath. They needed to start with the artifact. She gestured for Victor to join her, and then she picked up the artifact.

“It’s not vibrating anymore,” Evie said. She gripped it tight and then twisted.

Immediately, the stone walls of the room lit up, light seeping into the carved glyphs that spiraled out across the stone. It ran in rivulets, streaming toward a sculpture that was set into a sconce in the wall, its strange curves overlapping one another in disconcerting ways. Light flowed up the sculpture, pooling around a gap in the sculpture’s design. A hole.

“Wow,” breathed Saskia, her head tilted back, her face lit by the light. “Have you seen anything so beautiful?”

“I’m not liking the look of this,” Owen said, taking a heavy footstep toward the illuminated sculpture. “We need to act quickly and determine what this is. Protocol says we need to find a way to ensure whatever technology exists inside this place doesn’t fall into Covenant possession. Just because they can’t enter right now doesn’t mean they won’t be able to soon, and then eventually find a way to leverage this technology. So that needs to be our focus.”

But Evie barely heard him. The artifact was warm in her hands, the pulse of light pressing against her palm, as steady and comforting as a heartbeat. She drifted toward the sculpture. Lifted up the artifact. It felt like she was supposed to insert the artifact, but it wasn’t the right shape.

“What do you think?” Victor asked. “You think the artifact is some kind of activation device? That alone might keep the Covenant from accessing anything in here.”

“The light is the same color.” She tilted the artifact. The light didn’t move the way it did outside the structure, but rather pulsed steadily in its center. She frowned. She had to play with it to get it to access the map; maybe this was the same situation? She twisted the artifact again, and this time it elongated in her hand, the glass moving almost like liquid as it transformed into an octagonal shape. Some kind of nanotech, maybe? It didn’t look anything like human nanotech, that was for sure.

“Holy crap,” Victor said.

“Are you two okay?” Owen asked.

“We’re fine.” Evie lifted the artifact—not a cylinder anymore, she thought, but a key, oddly shaped but perfectly designed to slot into the sculpture. She glanced over at Victor. He nodded.

“Only one way to find out what this place is,” he murmured.

She took a deep breath, slid the key into place.

For a half second, nothing happened. But then Evie felt a weight pressing on her, as if the air had grown heavier. She reached out to steady herself against the wall, but her hand dipped into it, the stone a cold, sticky gel that clung to her skin. She screamed but did not hear it, only saw it—a metallic shimmer on the air that spiraled out of her mouth and exploded against the ceiling. She yanked out her hand, whipped around, panic squeezing her throat shut. Victor was no longer beside her—where the hell had he gone? There was Saskia, but she looked strange, elongated, her skin shimmery. And Dorian, his torso pressed into the wall, sinking straight into the stone. Evie screamed his name, and this time she tasted it, like blood at the back of her throat.

She lunged toward him, one hand reaching out—but she was on the ceiling now, hanging upside down like a bat. There was Victor, flattened out in the corner, black liquid streaming out of his open mouth.

And then Evie was splayed out on the floor, vomiting up stomach bile and the meager rations she had eaten a few hours earlier. Her head throbbed with a stabbing, intense pain. She retched, struggled to sit up. A wave of dizziness swept over her.

“We’ve got to get out of here now.”

Evie lifted her head to find Owen towering over her, the artifact in one hand. His stiff posture revealed his concern.

“You’re not sick,” she whispered. Was she the only one? No, she could hear Victor gagging beside her. He was curled up, his face ashy and beaded with sweat.

“That thing did something to you,” Owen said. “Can you stand?”

Evie shook her head, but she tried to push herself up anyway. Her arms trembled, and she lifted her head in a swoon. The doorway felt like it was across the world. Saskia was pressed against the wall, rubbing her head. Dorian was hunched over, vomiting into a corner.

And then Evie was flying. No—she was being carried. Owen carted her out of the structure, into the trench of dirt and mud outside. The hole. Gunfire popped overhead. The Covenant and the militia were still exchanging fire. Owen deposited her in a little carved-out section of dirt, keeping her out of sight. “Don’t move from here,” he said.

She slumped back, the dirt cool and soft. Her nausea was subsiding, but there was still a sharp, shooting pain lancing through her temple. She closed her eyes. Tried to ignore the rattle of gunfire on the surface.

Quickly, Owen brought out the others. They were all slumped and pale, hair damp with sweat, eyes fever bright.

“How are we—” It was difficult to talk. She tried to form words, but it felt like her mouth was full of cotton, and she couldn’t tell if she was moving her tongue the right way. “How are we going to get out—”

“We’re waiting,” Owen said, crouching down in the dirt. He deactivated his visor. Unlike everyone else, he looked fine. No sign of sickness. “As soon as it’s clear, as soon as you feel better, we’ll make a run for it.”

The gunfire exchange raged on overhead. Owen picked up his rifle, moved toward the entrance of the dig.

Evie just sank deeper into the dirt.

Three hours later, they were back at the camp, after a harrowing sprint through the last vestiges of the gunfight. Evie sat on top of her blanket with Saskia, drinking a tin of stale water. She felt significantly better than she had before, although her headache was still hanging on, a faint pain behind her right eye. Saskia seemed tired, but the color had come back into her cheeks, at least.

“That was—not what I expected to happen,” Victor said, settling down beside them.

“What did you expect?” Saskia asked.

“I don’t know.” Victor stared down at his water. “Not that.”

Farhi stomped over to them. “Spartan Owen needs to talk to you.” She studied them, her expression unreadable. The tables had turned, Evie thought: Because they were sniping from afar, none of the rest of the militia had faced any injuries. It was just them. Sickened by a few moments spent in an alien room.

“Now,” Farhi added, before crossing her arms, waiting for them to move. Evie stood up, legs shaking a little—she was still feeling weak from the sickness, as much as she didn’t want to admit it—and headed toward the office in the center of the building. That was always where Owen was when he wanted to talk to someone.

Dorian, shockingly, was already there when the others arrived, slumped at the table looking annoyed. Owen had set up the comm pad, the holo projector turned on, shining a beam of light into the air. Evie crept into the room, slid into the seat next to Dorian. He glanced at her, gave her a weak smile.

“Feeling better?” he asked.

She nodded. “You?”

“Nah.”

Owen cleared his throat. “Thank you all,” he said. “ONI has asked us to debrief with them.”

Evie felt a shudder of trepidation—ONI? Of course it made sense, but she didn’t want to think about what ONI would ask them to do, given how far the artifact from Brume-sur-Mer had taken them.

The holo shimmered with encryption static, and then a sharp, familiar face materialized. Captain Dellatorre. She smiled brightly at the group, and Evie’s trepidation grew stronger.

“Spartan-B096 has filled me in on some of what happened,” she said. “But as he was unaffected by the event, my science team and I would very much like to hear your experiences.” Three additional holos flickered on. “Allow me to introduce doctors Salo, Chapman, and Faraday.”

Each of the scientists nodded at the mention of their name. Dr. Salo, a broad-shouldered woman with a pile of thick, dark hair, smiled stiffly. “We’re very interested in knowing what happened.”

No one spoke. The captain’s hologram crossed her arms and stood very patiently, eyes flicking as if she were looking around the room.

“Someone’s gonna have to speak up,” Owen said. “I’ve told them everything I know. All I could see was what you four looked liked from the outside. And that’s not terribly useful for us to figure out what happened in there.” He shifted his weight. “It’s imperative that ONI fully understand what just happened. To make sure you four are safe, and to assess the possibility of the Covenant turning that structure—whatever it is—into a super-weapon.”

“What did we look like from the outside?” Saskia asked.

Owen’s expression hardened. “It’s hard to describe. Each of you looked … different. But all of you looked like you were being tortured.”

Evie sucked in a breath. It had felt like torture, hadn’t it? But then, she had barely understood what was happening to her. What was happening to the room—

“I’ll go first,” she said, leaning forward in her chair. Captain Dellatorre looked at her expectantly. “Once we inserted the artifact into the structure it felt like—like I was hallucinating.”

The others made murmuring noises of agreement, and Dr. Faraday raised an eyebrow. “Hallucinating? Did you see anything? Figures? Shapes? What?”

“No, no,” Evie said. “Well, sort of. I saw … sounds. Tasted them too. I saw Dorian melting into the wall. I saw—” The images flickered through her thoughts. “The wall melted into something else. Everything was merging together.”

“Yeah,” Saskia said. “I saw that too. It was almost trying to pull me in with it. Terrifying and painful.”

Evie looked at Saskia. “You saw the same thing?”

“Yeah,” Victor interrupted. “I saw Dorian embedded into the wall. And I was walking on the ceiling. You were too, Evie, and you looked all—distorted. Like a damaged holo-recording.”

“Jesus,” Dorian muttered. “We all saw the same thing.”

Blood rushed in Evie’s ears. “A shared hallucination?”

“Perhaps.” The voice of one of the scientists cut through the confusion—Evie didn’t see which one. “Spartan-B096, it seems their experiences line up with your reports as well.”

The other scientists murmured in agreement.

“What?” Evie almost jumped away from the table. “You saw all this too? But—you were unaffected!”

“It didn’t make me sick,” Owen said. “But I saw the … distortions, I would call them. Not just saw them. Experienced them. I had to … swim through the air to get to the activation device.”

“The sculpture you described,” Dr. Chapman said. “Correct?”

“Yes.”

“And what was the room like after Spartan-B096 removed the key from the activation device? What did do you notice?” asked Dr. Salo.

Evie shook her head. She didn’t remember anything about the room afterward. She’d been too sick. She only remembered the area outside, the soft dirt. It had seemed normal.

“It was changed,” Dorian said.

“What?” Evie looked over at him. “What do you mean?”

“I mean, it was changed.” He shook his head. “I thought I was still hallucinating since I felt like such garbage, but … there was a big indentation in the wall, where Saskia had been.”

Across the table, Saskia’s face went ashy.

“The ceiling was lower. It looked different—the way the floor looked. And the room just—”

“It felt different,” Saskia whispered. “I thought that. Like the air molecules had changed. You know how the air gets before a thunderstorm?”

Evie could hardly breathe. What had they done? She should never have inserted that artifact into the sculpture.

“It was only the room, though,” Evie said, breathless. “Outside was fine—”

“I observed that as well,” Owen said. “None of those changes seemed to happen outside the structure.”

“It’s a containment unit,” Saskia whispered.

Everyone turned to look at her. She lifted her gaze, her eyes wide. “Don’t you think? Like what my parents would use, when they were testing weapons—” She froze.

“Weapons?” said Captain Dellatorre in a flat voice. “You think this is a weapon?”

“I don’t—I don’t know. I just—doesn’t it seem like that, to you?”

“Perhaps,” the captain said.

“I don’t know.” Evie tapped her fingers against the table. Her mind whirred. “Especially since what we experienced was real. Isn’t that the kind of effect that can happen if there’s a slipspace drive failure?” Her heart was pounding. She wished she had paid more attention in her physics classes, but she’d always been more interested in running code to fix problems than unraveling the theoretical fabric of reality. However, she had read something once about failures with slipspace drives that sounded similar to what she had experienced in the structure. Slipspace was a compressed dimension of reality that was used by starships for faster-than-light travel, but it wasn’t as precise or as safe as humanity would have preferred. Was their experience connected to slipspace—a kind of breakdown of the physical world at a molecular level?

“You think we went into slipspace?” Dorian asked.

“No,” Saskia said. “We couldn’t have. It would have been much more dangerous. Right?” She looked at the scientists for confirmation.

“Absolutely,” said Dr. Chapman. “And your experiences don’t quite line up with the experiences of entering slipspace directly.”

“That’s what I thought. But I do think—” She looked up and met Evie’s eye. “I think the device is interacting with slipspace somehow. And that changed our reality.”

“How is that even possible?” Victor said.

“It’s alien tech,” Evie responded. “I think Saskia might be right. I think we—”

Made a huge mistake. She kept her mouth shut.

Saskia leaned forward, her face twisted in concentration. “We talked about this in Mrs. Veitola’s class. I remember. There’s a process that molecules can go through, where they change—it’s tied into slipspace somehow. Dammit!” She shook her head. “I spent hours cramming for that test.”

“I remember that,” Victor said. “It’s a chemical process. It’s supposed to be slow, though. It takes millennia.”

“You’re talking about Kulpinski’s theorem,” interrupted Dr. Chapman, his voice brimming with excitement. “That may not be totally relevant here, but the notion of changing molecules—” He turned away from the meeting, asked, “You’re getting all this down, right?” to someone out of view.

“This has been a fascinating physics lesson,” Captain Dellatorre said. “But I think we need to get away from the theoretical for the sake of time. What would be the purpose of such a device? One that could change molecules?”

“We would need more information before we could even begin to guess at something like that,” Dr. Salo said. “Perhaps the Forerunners used it for travel, or—”

“Or as a weapon?” Captain Dellatorre raised an eyebrow. The whole room went quiet. “Frankly, we aren’t concerned with what the Forerunners used the tech for. The Covenant want this thing. Clearly, they were unable to make it work without the Brume-sur-Mer artifact, and likely can’t even access it, which gives us the upper hand. But we have to ask ourselves what the Covenant would want with such technology.” She paused. Static ran through her holo. “We have to assume they’d be using it as a weapon.”

A weight dropped in Evie’s stomach. The blood rushed through her ears. A weapon. Of course. They’d been able to turn something about it on and off inside that structure. A power like that was unimaginable.

And in the hands of the Covenant?

“If they found a way to harness whatever happened in that room …” Victor said slowly, “they wouldn’t have to glass Meridian. They could do something so much worse. Tear it apart, or—”

“Not just Meridian,” Dorian said. “Any world in the galaxy. They could do whatever the hell they wanted to the entire human race.” He laughed bitterly. “No more war, right? Just shift molecules around until we never even existed.”

Captain Dellatorre gazed out at them from her holo. “This is worse than we feared.”

“So extract us!” Evie shouted, forgetting all protocol. “And the artifact. They can’t activate it unless they have the artifact.”

“For now,” Owen said. “There’s no reason to think they aren’t working on some other means of activation.”

“Then what are we supposed to do?” Evie cried.

“It’s a bit premature to assume that this structure could be used as a weapon in its current state,” Dr. Faraday said. “Most recovered Forerunner technology had strictly utilitarian use, and this technology more than likely restricted the structure itself for some enigmatically practical purpose. The real risk is that the Covenant would find a way to leverage the technology and weaponize it, as the captain mentioned. There’s only one way to know if they can.”

“We need to be able to study the structure,” the captain said, her voice unwavering and calm in the surge of panic filling up the room. “Owen, do you think it would be possible for us to secure the activation device in the structure itself?”

“And a piece of the structure’s wall,” added Dr. Chapman. “If it is a containment room.”

Owen frowned. “The activation device, possibly—it appeared to be separate from the building itself, and should be removable. As for the walls—” He shook his head apologetically at the scientists. “I can’t promise that.”

“Please try,” Dr. Chapman said, and the other two nodded in agreement.

“Very well,” said Captain Dellatorre. “Get us the activation device, the artifact from Brume-sur-Mer, and attempt to retrieve a piece of the structure’s wall. We are working on a plan of extraction—hopefully we should have an entry point within three days. That doesn’t give you much time.”

“Then it’s true,” Dorian said suddenly. “Meridian … it can’t be saved.”

He didn’t sound angry or upset, only resigned. The truth of what this meant for humanity was etched on his face. “It’s over once we take the Covenant’s super-weapon away. But if we don’t take it—”

Captain Dellatorre ignored the breach of protocol. “Spartan-B096, please notify us when preparations are complete. Dismissed.” The holo-light disappeared, casting them in half darkness.

Owen turned to the group. “You all have had to grow up fast these last three months, I know. I’m sorry that had to happen and I’m sorry for the people you’ve lost.” He zeroed in on Dorian, who glanced away. “But I told you, this war extends beyond the fate of one people, one world. This is about preventing our own extinction. The Covenant will stop at nothing to wipe out every colony until there’s nothing left of our species. If they find a way to use the technology in that structure, the last twenty-five years of fighting will be for nothing.” He paused, looking over the group. “We cannot let this power fall into the hands of the Covenant.”