A/N: This will be the last update for a week or so, as I will be very busy with work and Christmas things. I hope everyone has a happy holiday and takes some time to relax :)

2010.
Empty Chairs at Empty Tables.

Doug stared aghast at the flames in the pit below, noting the track for the Unstationary Scaffold that led right down into it. His mind went completely blank in horror. Even the cube had nothing to say.

"She's…" he spluttered at last. "She's just going to…kill them? Every test subject?" He began to pace, scrubbing his face with his hands. "But…that doesn't make any sense. Why would She do that? It's counterproductive." Turning his attention back to the girl, he moaned, "Oh god, I have to do something. I have to fix this. How can she possibly get out of there?"

"You need to calm down," the cube instructed, its tone firm. "You know it gets worse when you panic."

Already fighting the rising hum of other voices, Doug nodded, trying to control his breathing.

"You can do this," the cube told him. "Just think. Take another look around. Think like a scientist. Or…a rational man, at least."

He let out a shaky breath. "Okay. Okay."

He approached the glass, looking down into the fire pit, searching the entire space from burning floor to high ceiling. There was a broken wall above, leading into what looked like one of the engineering areas.

"Potential escape route for her," the cube said, sounding optimistic.

"Yes, but she has to get here first," he shot back, biting his lip anxiously as he scrutinised the space. A jolt went through him, a spark of faint hope. "Wait…those walls. They're portal-compatible. And so are these back here. They didn't bother constructing walls out of expensive brown gloss tiles just to let them burn," he realised, "they used the cheaper alternative because they didn't think there was any way out." His face broke into an unexpected grin. "But there is, if we break this glass."

"That's going to be easier said than done though, right?" the cube said. "We don't have anything heavy enough to hit it with."

"We don't need anything," Doug replied, setting it down against the back wall, bag and all. "We're next to a turret repair workshop."

The cube's tone brightened. "Ah!"

He went back through the door and picked up one of the deactivated turrets from what looked like the 'completed' shelf. He'd seen them before, but he had very little experience of actually working on them. Making sure to keep behind it, he set it down and flicked the switch. At once, a thin line of ruby red appeared, hitting the wall ahead, and a sweet little voice said, "Sentry-mode activated."

Doug carefully picked it up by its leg struts, holding it far out in front of him.

"Hey!" it protested indignantly.

"Don't you 'hey' me," he growled, taking it back through to the platform above the incinerator.

He put it down facing the glass. The turret's laser sight moved gently from side to side, but it didn't fire, soon settling back into sentry-mode.

A voice let out a peel of mocking laughter, and Doug knew exactly what he needed to do.

"Great," he muttered sardonically, moving as far to the right as he dared.

"Be careful!" the cube cried.

"I intend to."

Taking a deep breath, he darted out in front of the turret.

"There you are," it stated happily.

Doug dove wildly to the side as a line of bullets pelted the glass wall. Clumsily, he crawled back out of the turret's range, then glanced up to see the damage. The line of holes was quite neat, each with spider-webbing cracks spreading out from the centre.

"It's not bullet-proof," he pointed out in relief. "Just toughened."

"Did you think it was?"

"I thought it was a possibility."

"Nap time," the turret declared, closing its side panels.

Doug got to his feet and moved the turret into the far corner, its laser sight searching nothing but wall. Then he retrieved a heavy wrench from the repair workshop and stood in front of the bullet holes, testing its weight in his hand.

"Make it count," the cube advised. "We're running out of time."

"I know."

After a few practice swings, Doug gripped the wrench tightly, raised it, then brought it down with as much force as he could muster. The glass was reinforced, but it wasn't invincible. On his third hit, the cracks crept across its entire surface, shooting upwards like lightning bolts. Then, in one single motion, the entire wall broke into pieces and fell into the fire below. Doug just had time to skip backwards before he was pelted with shards of flying glass, and he covered his head with his arms.

The noise was tremendous, and he felt sure that GLaDOS would be instantly aware of what he'd done, but that was okay. He didn't intend to stick around. He walked the length of the platform, kicking leftover pieces of glass into the fire, mindful of the fact that the girl wasn't wearing shoes. Nodding in satisfaction, he swung the cube onto his back again.

"Wait!" it said. "The turret."

Doug halted, glancing over his shoulder. "Oh. Right."

He went back and picked it up, once again holding it ahead of himself as he walked towards the gap where the glass had been.

"Please put me down," the turret protested.

"Oh, I intend to," he muttered, well aware that it wasn't sentient. It just made a change to speak to something that wasn't the cube.

He leaned cautiously over the railing that now served as the only barrier between the platform and the fire pit. The heat was intense, and he squinted, feeling the skin on his cheeks burn. He dropped the turret into the flames, where it spluttered out a few bullets before promptly exploding.

"Let's get out of here," he suggested, backing away from the hot air.

"What now?"

"I'm going back for my meds, then we stay ahead of the test subject and make sure her route is clear."

"I'm not sure we have time to go back to the locker room," the cube said, its voice surly.

"It's not far. We'll make it," Doug replied firmly.

"I don't know what you think you've achieved, Rat Man," GLaDOS cut in, sounding too close for comfort.

Doug jumped violently and ran for the door.

"But I very seriously doubt it's anything other than mindless vandalism. I'd take it out of your pay, but we both know that money only has meaning in the real world, and you won't be getting back there any time soon."

He slammed the door on her words, dashing back through the turret repair room and out into the corridors. The talkative supercomputer didn't know what he was up to, had no way of knowing that Her death trap now had an escape route. That was enough to hearten him, despite Her taunting. Doubt swam to the fore, though, questioning whether he'd done all he could to keep the girl safe, whether she'd be quick enough to see the way out. He tried to shake the feeling off. He had to trust her. It had been sufficient in the past, back when…

Stop it. Focus.

With great difficulty, Doug pushed his emotions aside, choosing instead to keep his goal in mind. Putting on an extra burst of speed, he ran back towards the locker, towards a clearer head.

Chell, meanwhile, was busy euthanizing her companion cube, inwardly smirking at GLaDOS's attempts to make her believe that it was painful to do so. It was just a cube with a pink heart on it. No big deal.

Listening to the A.I.'s speech with half an ear, she sauntered to the elevator, now as comfortable in the leg springs as she was in shoes. Her face was still passive, but her mind was working overtime. The observation offices remained empty, sending another bout of concern through her every time she checked. She knew GLaDOS was in charge. It was abundantly clear. What was still unknown was what had happened to everyone else, not to mention how much time had passed. Chell didn't feel any older, nor did she look it, based on the few glimpses she'd caught of herself when she'd placed portals at certain angles, but she wasn't stupid. She realised that she probably wasn't the first test subject to pass through the chambers, and GLaDOS seemed quite comfortably established in her role.

Someone had been leaving warnings for test subjects, manipulating the wall panels to allow access to small rooms behind the chambers. The wild scribbles, often making very little sense, were the only sign of humanity that she'd seen so far. Whoever it was had become far more attached to their companion cube than she had been, leaving tributes to it all over the place. She couldn't find it in her heart to be too derogatory towards them, though, since they'd also left her half a bottle of clean water that had been very welcome.

Chell leaned against the wall of the elevator, awaiting her arrival at chamber eighteen.

So close, she thought. I just need to keep my focus until the end.

It was difficult to put her worries aside, though. She was scared to discover what had happened outside the test chambers. If GLaDOS was in charge, she could probably assume the worst. There was no way that Doug would have left her in Test Subject Storage if everything had gone fine with the launch. He'd promised her that he'd save himself if something went wrong, but how successful had he been? And if he had been successful, where was he now? And her father… She'd been so angry with him and his misplaced ideals, but it had all but evaporated now, in the face of her fear. She would happily throw it all aside just to know that he was okay.

Deep in her heart, she knew the truth, but she refused to acknowledge it. Doing so would make it seem real. She had no proof yet, and she needed to keep her attention on the tests. Otherwise she'd come to a sticky end. Fortunately, chamber eighteen was large and complex enough to keep her on her toes.

Chamber nineteen harboured the biggest wake-up call of all.

Patiently waiting for his medication to kick in, Doug was once again in the fire pit room, this time crouched high above the flames beside the huge gap in the wall opposite the now-accessible platform lower down. He was edgy, knuckles white where he gripped broken pipes for support. He knew it was unwise, but he had to wait and see that she was okay.

"I hear something!" the cube said excitedly.

"It's Her," Doug spat. "Lying about the cake again. It won't take the girl long to solve this one."

His palms were clammy, so he wiped them on his lab coat, swallowing a nervous lump in his throat.

She's going to die, whispered a voice. Like the rest of us. You can't save anyone.

"Shut up," he hissed.

You didn't even try. Now it won't make any difference.

"It's okay," the cube soothed. "You just need to stay calm."

"Well I can't," he snapped. "She might die. She might…"

"She might not," the cube countered. "You said you had to trust her, so trust her."

"Too late now anyway," he murmured, hearing GLaDOS's chilling speech of farewell.

The unstationary scaffold drifted into view, the slender, orange-clad figure standing in its centre, her ponytail whipping round as she quickly took in her surroundings.

"Come on," Doug whispered. "Come on, Chell. Stay alive."

He didn't even register that he'd used her name, eyes fixed on her form as it slid closer and closer to the flames. He was beginning to fear that she wouldn't make it, but then she lifted the barrel of the portal gun, shooting a loop of brilliant blue into the wall just above the platform ahead of her. Pivoting fast, she shot a beam of orange into the wall to her left, took a single step back, then launched herself forward. She leapt gracefully through the portal, landing safely on the platform, her leg springs absorbing the impact. She was breathing fast, clearly shaken up.

GLaDOS also seemed taken aback, her voice glitching slightly before she tried to ad-lib her way through what had happened.

Chell began searching for a way out, her gaze sweeping the walls.

Doug shot to his feet, moving out of her view. He couldn't afford to be seen, not even by her. He pelted up a short flight of steps into the next area, then took the following stairs two at a time, running up to a small gantry leading to an unlocked door. This he left slightly open, so that the girl would find her way easily. It led through to another turret repair workshop, but he didn't stop to look around, running up the next set of stairs as quickly as possible, knowing that she was now mere feet behind him. There was one door at the top and a second one guarded by a padlocked gate. She would be able to portal through the mesh, which would take her, eventually, to some of the Test Subject Observation and Care offices. He trusted that she would be able to bypass the huge fans and the pool of toxic gunk that had collected on the bottom floor.

He jabbed his code into the rewired keypad next to the other door, yanking it open and darting inside before she could catch him up. He shot up another short flight of stairs and crawled through the vent that he'd left open for himself. It was a tight fit for the cube, which scraped along the floor and ceiling as he pulled it awkwardly behind him, but eventually he emerged in an area with an observation window down to the toxic pool.

Heading down the stairs in front of him, he glanced down at the room she would enter the area by, noticing the graffiti he'd drawn last time he'd visited: a running stick figure and a scarlet arrow pointing up, so she'd know to get herself to the top gantry. The stairs had collapsed since he'd last ventured there, eroded by time and lack of use, not to mention whatever fumes the toxic goo was giving off. Through the window, he saw the girl step out of a portal, try the locked door next to her, then begin searching the walls for where to place her next.

"She's doing well," the cube commented warmly.

"She is," he agreed, managing a trace of a smile. "Let's keep going, she'll be here soon."

Doug took the stairs behind him, leading up to a dead end where one of the glass tubes could be seen, cubes and other equipment occasionally passing through it. He'd scrawled on this wall too, his frantic message about the promise of cake being a lie. He'd been in a particularly wild state of mind that day, unable to exert even the tiniest bit of control over the buzz of voices in his head. It had seemed of utmost importance that the test subject realise that she was being lied to. He'd forgotten that she would already know that.

"Where does this tube lead?" he mused aloud. "Is there any way to control which direction it takes?"

"The panel on the wall," the cube suggested, "there. Turn off the other propulsion units."

"Yes!" he hissed, darting over to the panel, wrenching its protective cover open. Fingers flying over the buttons, he said, "This tube leads to the cube dispenser in test chamber nine, among other places. She beat that once, she can do it again."

"But what then? She'd be back where she started."

"If we keep the elevator elsewhere, she can get out down the lift shaft. That would take her..." he trailed off, calling the layout of the place to mind. "...Into the area with the pistons. That's going to be hard for us to navigate. I barely made it alone, last time."

"Did you leave her a message though?"

"I think so. I can't really remember. If I did, it was just arrows."

The cube made a soft, thoughtful noise. "She'll make it, I'm sure. But what about us?"

As he talked, Doug worked steadily to turn off all the propulsion units except for the ones that would take her to chamber nine. "We can go the back way and catch up with her later. There!"

A quick check through the observation window showed that the girl was still exploring the Test Subject Observation and Care offices. Doug hurried back to the tube and hopped lightly over the railing that guarded it.

"Careful," the cube warned.

"I will be."

Holding onto the wall for balance, he kicked forcefully at the glass. Unlike the reinforced stuff that he'd found in chamber nineteen, this was regular glass, which cracked within moments. Doug's leg lurched down as it gave way, and he was forced to grab the railing to stop himself falling in. Fighting the tug of the propulsion system, he hauled himself back over.

"Good job," said the cube. "Now let's go. She'll see us if we're not careful."

"I know, I know."

He headed back down to the vent he'd come in by, climbing in and replacing its slatted cover. Retreating back around the nearest corner, he hid there until he heard the faint tapping of the test subject's leg springs disappear up the stairs. When he cautiously peeked out again, it was just in time to see her vanish into the broken tube.

"Time to go," he said briskly.

Chell walked through Test Subject Observation and Care with an expression of horror on her face. It looked nothing like she remembered it, save for the observation rooms themselves. Whole sections of the walkways had dissolved into the toxic waste that now covered the floor of the lower level, and doors that would have let her through to corridors she recognised were inaccessible, submerged under the goo. Everywhere was deserted, chairs tipped over at tables that still had unfinished work scattered across them. In one of the conference rooms, a slide show was still looping, watched only by half-finished notes and empty coffee mugs.

It was all deeply unnerving, and seemed to confirm her worst fear. She ventured into the observation offices and looked down at tests she'd already solved. On the wall, she found Hannah's stupid jellyfish cartoon that she'd doodled when Adam's back had been turned. Chell traced her fingers over it, her hands trembling slightly as she considered what had most likely happened to them both.

She plopped down on a desk chair for a quick rest, knowing she couldn't linger for long. Looking around at the silent, abandoned workspace, she felt more alone than ever.

"Doug," she whispered. "Where are you?"

Her hope for him was the hope she clung to the most, as he had promised her he'd survive. She wanted to believe that he wouldn't let her down, and she needed to believe in something. She had no plan. She was blindly following the notes left by someone who seemed to know their way around, hoping it would lead to an exit, or at least to somewhere she recognised.

Wearily, she got up and exited the suite of offices, crossing the walkway over what had once been the lower floor, but was now the most foul-smelling cesspit she'd ever experienced. After portalling her way up to a series of gantries and stairs, she found more graffiti, accompanied by handprints above a broken transport tube. Leaning forward over the railing there, she lightly pressed her palm against one of the prints. It was slightly bigger than her own hand, its fingers longer. Most likely a man, then, as Chell considered herself to have average-sized hands for a woman, not that she'd ever put much thought into it. When she pulled back, her palm was dotted with black ink.

She froze, wide-eyed. The prints were fairly new, as recent as…well, however long it took ink to dry. She didn't think that was very long at all. They had been here, possibly while she'd been resting in the offices below. But where had they gone? Down into the tube? It seemed the only way.

Gingerly, she climbed over the railing and looked sceptically at the tube. It reminded her of the water flumes she'd used to ride at the swimming pool during school break. She'd never much cared for them, feeling a little like a spider washed down the drain. But there was no choice here. Gripping the portal device tight to her chest, she dropped down into the hole, tucking her legs up. Floating along on a current of air, she rode across Test Subject Observation and Care, hoping she was fast on the trail of the mysterious message-writer. No one else was going to give her any answers.

A/N: Points for you if you know where I got this chapter title from :)