For some period of time—minutes, hours, Clarke wasn’t sure—all she could hear was the sound of their hearts, the whisper of their mingled breaths. But then a scream clawed its way out from the clearing, dragging them apart. Clarke and Wells jumped to their feet, Clarke holding on to Wells’s arm for balance as the world slid back into terrifying focus.

He grabbed her hand and they ran back into the clearing. She heard more screams, but none were as frightening as the roar and crackle that made every nerve in her body stand at attention.

Flames rose up from the tents, some of which had already collapsed into smoldering heaps, like corpses on an ancient battlefield. Shadowy figures sprinted for the safety of the forest, pursued by tendrils of hungry flames.

Thalia, Clarke thought in horror, and started to run. She was too weak to make it out of the infirmary tent on her own.

“No!” Wells shouted, forcing his voice over the chaos of screams. “Clarke, it’s not safe!”

But his words slid off her like a spray of ash. She made a beeline for the tent, smoke filling her lungs, blinking to see in the smoldering air.

His arm wrapped around her waist like a steel band, pulling her forcibly into the shelter of the trees. “Let me go,” she shrieked, thrashing with all her might. But Wells held her tight, forcing her to watch helplessly as fire engulfed the infirmary fewer than a hundred meters away. The entire side of the tent was up in flames. The plastic tarp on top was melting, and smoke filtered out of the gap between the front flaps.

“Get off.” She sobbed, twisting again as she tried to wrestle free.

He slid his arm under her and began dragging her backward. “No,” she shrieked, feeling the sound tear her throat, pounding at him helplessly with her fists. “I need to get her out.” She dug her heels into the grass, but Wells was stronger, and she couldn’t hold her ground. “Thalia!”

“Clarke, I’m so sorry,” Wells whispered in her ear. She could tell he was crying, but she didn’t care. “You’ll die if you go in there. I can’t let you.”

The word die ignited a reserve of power that exploded through her. Clarke gritted her teeth and lunged forward, momentarily escaping Wells’s hold. Her entire being had reduced to a single, desperate thought—saving the only friend she had left in the universe.

She screamed as her arm was wrenched behind her back. “Let me go.” This time, it was more of a plea than an order. “I’m begging you. Let me go.”

“I can’t,” he said, wrapping his arms around her again. His voice was shaking. “I can’t.”

The clearing was empty now. Everyone had made it into the woods, taking whatever supplies they could carry. But no one had thought to grab the frail girl who was now being burned alive just a few meters away.

“Help,” Clarke cried. “Someone, please help.” But there was no answer Mom?e gexcept for the roar and crackle of the fire.

The flames on the top of the infirmary tent rose higher, the sides collapsing toward each other, as if the fire were inhaling the tent and everything inside of it. “No.”

There was a crack, and the flames shot up even higher. Clarke shrieked with horror as the entire tent collapsed into a storm of fire, then slowly crumbled into ash.

It was over.

As she walked away from the medical center, Clarke could almost feel the vial pulsing in her pocket, like the heart in the old story Wells had discovered at the library the other day. He’d offered to read it to her, but she’d flatly refused. The last thing she needed right now was to hear creepy pre-Cataclysm literature. She had enough scenes of horror playing out in her real life.

The vial Clarke carried in her pocket could never have a heartbeat, she knew; just the opposite. The toxic cocktail of drugs inside was designed to stop a heart for good.

When Clarke got home, her parents weren’t there. Although they both spent most of the day in their lab, over the past few weeks, they’d conveniently found excuses to leave right before Clarke returned from her training and rarely came back until just before she went to sleep. It was probably for the best. As Lilly grew sicker, Clarke could barely look at her parents without feeling a surge of rage. She knew she wasn’t being fair—the moment anyone protested, the Vice Chancellor would have her parents executed and Clarke Confined within days. But that didn’t make it any easier for her to meet their eyes.

The lab was quiet. As Clarke wound her way through the maze of empty beds, all she could hear was the drone of the ventilation system. The soft buzz of conversation had faded as more and more bodies were secreted away.

Lilly seemed even thinner than she’d been the day before. Clarke crept toward her bed and ran her hand gently down her friend’s arm, shuddering as bits of her skin fell away. She slipped her other hand into her pocket and wrapped her fingers around the vial. It would be so easy. No one would ever know.

But then Lilly’s pale lashes fluttered open, and Clarke froze. As she stared into Lilly’s eyes, a cold wave of terror and revulsion crashed over her. What was she thinking? An overpowering urge to destroy the vial tore through her body, and she had to take a deep breath to keep herself from hurling it against the wall.

Lilly’s lips were moving, but no sound was coming out. Clarke leaned forward and gave her a small smile. “Sorry, didn’t catch that, Lil.” She lowered her head so her ear was closer to Lilly’s mouth. “What did you say?”

At first, Clarke could only feel the soundless wisp of air on her skin, as if there wasn’t enough breath in Lilly’s lungs to push the words out of her mouth. But then a faint moan escaped from her chapped lips. “Did you bring it?”

Clarke raised her head to look into her friend’s panic-filled brown eyes. She nodded slowly.

“Now.” The word was barely audible.

“No,” Clarke protested, her voice shaking. “It’s too soon.” She blinked back the tears that had begun to fill her eyes. “You could still get better,” she said, but the lie sounded hollow, even to her.

Lilly’s face contorted in pain, and Clarke reached for her hand. “Please.” Lilly’s voice was ragged.

“I’m sorry.” Clarke gave Lilly’s fragile hand a gentle squeeze as tears began to trickle down her cheeks. “I can’t.”

Lilly’s eyes grew wide, and Clarke inhaled sharply. “Lil?” But Lilly remained silent, staring at something only she could see. Something that filled her eyes with terror. The physical pain racking Lilly’s body was terrible, Clarke knew, but the hallucinations, the demons who were with her every moment, hovering at her bedside, were worse.

“No more.”

Clarke closed her eyes. The guilt and remorse she’d feel could never compare to Lilly’s pain. It’d be selfish to let her own fear prevent her from bringing her friend the peace she wanted—the respite from pain she deserved.

Her whole body was trembling so hard, she could barely remove the vial from her pocket, let alone fill the syringe. She stood next to the bed and clasped Lilly’s hand with one arm, using the other to position the needle over Lilly’s vein. “Sleep well, Lil,” she whispered.

Lilly nodded and gave Clarke a smile that she knew would be burned into her brain for the rest of her life. “Thank you.”

Clarke held Lilly’s hand for the few minutes it took for her friend to slip away. Then she rose and placed her fingers against Lilly’s still-warm neck, searching for a pulse.

She was gone.

Clarke sank to the damp ground, gasping as her lungs reached desperately for the cool air, then rolled onto her side. Through the tears blurring her vision, she could make out the shapes of people standing all around her, their dark, featureless silhouettes still and quiet.

Her best friend, the only person who truly knew Clarke, who knew what she had done to Lilly and still loved her. Thalia had told her to make things right with Wells tonight—and then Wells had held Clarke back while they watched Thalia die.

“I’m so sorry, Clarke,” Wells was saying, reaching for her. She pushed his hand away.

“I can’t believe you,” she said, her voice cold and quiet. Rage billowed in her chest, as if there were flames inside her that needed only fury and grief to blaze into an inferno. “There was no way you’d make it,” Wells stammered. “I just—I couldn’t let you go. You would’ve been killed.”

“So you let Thalia die instead. Because you get to decide who lives and who dies.” He started to protest, but she kept going, shaking with rage. “Tonight was a mistake. You destroy everything you touch.”

“Clarke, please, I—”

But she just stood up, shaking the bits of cinder from her clothes, and walked into the forest without looking back.

They all had ash in thhad ash eir lungs and tears in their eyes. But Wells had blood on his hands.