Gasping, Glass staggered down a passageway bordered by unmarked doors. Her right knee buckled, and she grabbed on to the wall to catch herself. The corridor was beginning to grow blurry. She turned her head and could just make out the shape of an air vent. Glass hooked her fingers under one of the slats and pulled. Nothing happened. With a groan, she pulled again and felt the metal grate give. She yanked it open, revealing a dark, narrow tunnel full of ancient-looking pipes.

Glass pulled herself onto the small ledge, then scooted along on her stomach until there was room to bring her knees up to her chest. The metal felt cool against her burning skin. With her last milligram of strength, she crept deeper into the tunnel and closed the vent behind her. She strained her ears for signs of pursuit, but there was no more shouting, no more footsteps, only the desperate thud of her heart.

Glass blinked in the near darkness, taking stock of where she was. The cramped space extended straight in both directions, thick with dust. It had to be one of the original air shafts, from before the Colony built their new air circulation and filtration systems. Glass had no idea where it would lead, but she was out of options. She started to crawl forward.

After what felt like hours, her knees numb and her hands burning, she reached a fork in the tunnel. If her sense of direction was right, then the tunnel on the left would lead to Phoenix, and the other would run parallel to the skybridge—onto Walden, and toward Luke.

Luke, the boy she loved, who she’d been forced to abandon all those months ago. Who she’d spent every night in Confinement thinking about, so desperate for his touch that she’d almost felt the pressure of his arms around her.

She took a deep breath and turned to the right, not knowing if she was headed toward freedom or certain death.

Ten minutes later, Glass slid quietly out of the vent and lowered herself to the floor. She took a step forward and coughed as a plume of dust swirled around her face, sticking to her sweaty skin. She was in some kind of storage space.

As her eyes adjusted to the darkness, shapes began to materialize on the wall—writing, Glass realized. She took another few steps forward, and her eyes widened. There were messagescarved into the walls.

Rest in peace

In memoriam

From the stars to the heavens

She was on the quarantine deck, the oldest section of Walden. As nuclear and biological war threatened to destroy Earth, space had been the only option for those lucky enough to survive the first stages of the Cataclysm. But some infected survivors fought their way onto the transport pods—only to find themselves barred from Phoenix, left to die on Walden. Now, whenever there was the slightest threat of illness, anyone infected was quarantined, kept far from the rest of the Colony’s vulnerable population—the last of the human race.

Glass shivered as she moved quickly toward the door, praying that it hadn’t rusted shut. To her relief, she was able to wrench it open and began dashing down the corridor. She peeled off her sweat-soaked jacket; in her white T-shirt and prison-issue pants, she could pass for a worker, someone on sanitation duty, perhaps. She glanced down nervously at the bracelet on her wrist. She wasn’t sure whether it would work on the ship, or if it was only meant to transmit data from Earth. Either way, she needed to figure out a way to get it off as soon as possible. Even if she avoided the passages with retina scanners, every guard in the Colony would be on the lookout for her.

Her only hope was that they’d be expecting her to run back to Phoenix. They’d never guess that she would come here. She climbed up the main Walden stairwell until she reached the entrance to Luke’s residential unit. She turned into his hallway and slowed down, wiping her sweaty hands on her pants, suddenly more nervous than she’d been on the dropship.

She couldn’t imagine what he’d say, the look he’d give her when he saw her on his doorstep after her disappearance more than nine months earlier.

But maybe he wouldn’t have to say anything. Perhaps, as soon as he saw her, as soon as the words began to pour out of her mouth, he would silence her with a kiss, relying on his lips to tell her that everything was okay. That she was forgiven.

Glass glanced over her shoulder and then slipped out the door. She didn’t think anyone had seen her, but she had to be careful. It was incredibly rude to leave a Partnering Ceremony before the final blessing, but Glass didn’t think she’d be able to spend another minute sitting next to Cassius, with his dirty mind and even fouler breath. His wandering hands reminded Glass of Carter, Luke’s two-faced roommate whose creepiness only slithered out of the darkness when Luke was out on guard duty.

Glass climbed the stairs toward the observation deck, taking care to lift the hem of her gown with each step. It’d been foolish to waste so many ration points collecting the materials for the dress, a piece of tarp that she’d painstakingly sewn into a silver slip. It felt utterly worthless without Luke there to see her in it.

She hated spending the evening with other boys, but her mother refused to let Glass be seen at a social event without a date, and as far as she knew, her daughter was single. She couldn’t understand why Glass hadn’t “snatched up” Wells. No matter how many times Glass explained that she didn’t have those types of feelings for him, her mother sighed and muttered about not letting some badly dressed scientist girl steal him away. But Glass was happy that Wells had fallen for the beautiful if slightly overserious Clarke Griffin. She only wished she could p hd she ctell her mother the truth: that she was in love with a handsome, brilliant boy who could never escort her to a concert or a Partnering Ceremony.

“May I have this dance?”

Glass gasped and spun around. As her eyes locked with a familiar pair of brown ones, her face broke into a wide smile. “What are you doing here?” she whispered, looking around to make sure they were alone.

“I couldn’t let those Phoenix boys have you all to themselves,” Luke said, taking a step back to admire her dress. “Not when you look like this.”

“Do you know how much trouble you’ll get in if they catch you?”

“Let them try to keep up.” He wrapped his arms around Glass’s waist, and as the music from downstairs swelled, he spun her through the air.

“Put me down!” Glass half whispered, half laughed as she playfully hit his shoulder.

“Is that how young ladies are taught to address gentlemen admirers?” he asked, using a terrible, fake Phoenix accent.

“Come on,” she said, giggling as she grabbed his hand. “You really shouldn’t be here.”

Luke stopped and pulled her to him. “Wherever you are is where I’m supposed to be.”

“It’s too risky,” she said softly, bringing her face up to his.

He grinned. “Then we better make sure it’s worth our while.” He placed his hand behind her head and brought his lips to hers.

Glass raised her hand to knock a second time when the door opened. Her heart skipped a beat.

There he was, his sandy hair and deep-brown eyes exactly as she remembered them, exactly as they’d appeared in her dreams every night in Confinement. His eyes widened in surprise.

“Luke,” she breathed, all the emotion of the past nine months threatening to break through. She was desperate to tell him what had happened, why she’d broken up with him and then disappeared. That she’d spent every minute of the nightmarish last six months thinking of him. That she never stopped loving him. “Luke,” she said again, a tear sliding down her cheek. After the countless times she’d broken down in her cell, whispering his name in between sobs, it felt surreal to say it to him.