ALYX
  How long he had slept—how he had even managed to sleep—Gordon was unsure. The sound of the tracks clattering somewhere underneath the boxcar must have lulled him. And he had been moving nonstop for so long now; no wonder exhaustion had finally claimed him. But suddenly the pitch of things changed. must have been some hint of it, reaching into his dreamless sleep like a premonition, for he woke a moment before there was any overt reason to awake. He was still alone in the munitions car, hidden among the crates and canisters, all of it gently shuddering from side to side, the smell of machine oil and the stink of diesel filling the air He was hungry, with his meal at Eli's now many hours behind him, and it was cold, as if the suit's regulators were not functioning properly. He was beginning to develop a dread that the HEV suit might crap out at any moment, leaving him stranded, with its mnemoflex joints frozen into a rigid state, its autolocks dead. Here he would lie, awaiting the arrival of the guards like the rest of the cold unmoving crates in the car.
  But the dread had little time to develop, as the explosion cut it short.
  The train rolled sideways, flung from the track. The crates that had shielded him now flew away from him, and he curled into a ball to let the suit protect as much of him as possible from the heavy containers. Even several of the cases strapped to the walls or bolted to the floors tore loose in the moment, the Immense torque shearing steel bolts clean off. Gordon came to rest as an alarm whistle shrilled; he had managed to land on top of a cabinet the size of a refrigerator. He could hear shouts, gunfire, more explosions in the distance. He stood up on the cabinet, reaching for the side loading door which was now directly overhead; he could barely reach it, and knew there was little chance that it would budge, even with better purchase.
  Suddenly bootsteps clamored across the door. Paused. He imagined soldiers up above, swarming to protect their shipment. Something clanked down on the thick metal with a maddeningly familiar sound. Where had he heard it before?
  The faint high-pitched whine of an activated detonator brought the memory into clear focus.
  Gordon leapt for the farthest corner of the car, sheltered by the cases that had nearly killed him, hoping that now they would save his life. The blast came the instant he hit metal. Shrapnel seared the back of his head; there was an acrid tang that sent him up coughing. It was partially from the open air, partially from the explosive. He rose up involuntarily, wracked with fumes, and saw the night sky above him. The current ceiling (once wall) of the boxcar gaped inward like a scorched metal flower. There was a pair of legs dangling in past the sharpened petals. Legs sheathed in black, heavy boots swinging back and forth as if the wearer had just dropped down at the edge of a pond to fish. But instead of a fishing pole, there was a gun trained down on him, its laser sight picking him out in the smoldering dark. He shaded his eyes from the red beam, and heard a soft voice whisper something like, "Check him, Snitch."
  Gordon gasped as a thing hopped down into the car and came toward him, hopping from crate to crate as it sniffed him out. It looked wet, permanently; the colors were of a toxic brilliance; he couldn't find the eyes, but it had far too many teeth. It crouched above him, flicked its tongue out for a taste, and he felt an acid welt begin to rise across his cheek.
  "Don't move," said the person above him. "One bite and you'll be dead by your next breath."
  Then he heard a thud, and the figure dropped in. He knew instantly—even with the heavy black gear, the belts of ammo, the goggles and the short-cropped hair—that it was a woman. She crept up until she was next to her pet. She made a click with her tongue, as if gentling a horse, and the thing wound around and flowed onto her shoulder, settling itself there like a glistening stole.
  A light clicked on, blinding him. And she gasped.
  "You!" she said. "What're you—"
  At that moment they both heard footsteps outside—grinding through cinders, it sounded like. She switched off the light and he felt a gloved hand over his mouth. As if he needed silencing. The steps were coming closer, but there were no voices; they must have had a way of communicating silently. He had no doubt the car was being surrounded.
  "All right" she whispered, "I'm going to trust you. I can use some help carrying stuff anyway. Take this, and come on up."
  She unhooked something from her belt; Gordon felt a weapon pushed into his hand. He wasn't sure what it was, but he found a trigger, and that was enough to get started. She gave him her hand and he scrambled up onto the box as quietly as he could. She hooked her fingers over the edge of the blasted opening hauled herself up, knelt there in silhouette on the top of the car. As Gordon started up, she began yanking grenades from her belt and lobbing them down into the shadows around wherever the car had come to rest. The explosions were mixed with the sound of metal tearing and ragged screams. Gordon rose up beside her, firing down at the figures moving below. The faint light that pervaded the open tracts of wasteland gleamed on metal, but he couldn't be sure they weren't men as well. It was over in a few moments; she had an uncanny accuracy with the grenades that didn't seem to be entirely related to their advantage of height.
  "More on the way," she said. "Big ones. Let's stock up and get out of here."
  She ducked back into the boxcar. He heard a muffled explosion as she blasted open a container down below, then she started tossing smaller cases up to him. A moment later she was up again.
  "Oh, I'm Alyx," she said, stuffing the cases into random pockets on her outfit. "l already know who you are. And I think I can probably guess where you're going."
  She pointed out a mounded shape, just visible through the enveloping smog; it looked like the shell of a vast slumbering beetle; a streamlined mountain of corroded metal. From the density of the fumes, the stink in the air and the burning in his eyes, he suspected he had arrived at what Eli had called, "The Air Conditioner."
  Alyx tensed and got to her feet, swinging her gun down into her hand. Something was coming. Out on the horizon, jaunting through the fog with a long-legged gait, more than one of them. He squinted, making out what looked like an enormous tripod, surmounted with a huge body, a faint sheen of lenses. He thought of Dog, briefly; one of Dog's cousins, at the height of its powers. There was a sullen flash deep in the eye of the distant thing, and suddenly he and Alyx were flung from the roof of the car. He came down hard in the cinders, lay there dazed for a moment, wondering where he was, until suddenly he felt tiny needles biting into his ear.
  He came back to himself, pushing her little beast, Snitch, away from his head. The cub darted back, licking its jaws, baring the hypodermic teeth.
  "She just gave you an adrenaline injection," Alyx said, holding out her arm as the thing climbed back up to her shoulder. "l didn't think you'd mind. Right now, we're going to need to run."
  From the far side of the boxcar, the first of the tripods rose up and trained its eye upon them. The eye began to warm again, cycling up for another burst. Alyx had already scrambled away Gordon was on his feet and running an instant before the thought of flight crossed his mind.
  The landscape was coated in a poisonous residue, cinnabar and sulfur and whatever other precipitates came sifting down from the Combine's atmospheric reprocessor. Caustic particles drifted in a steady snow. Gordon clambered up a slope that crumbled into greenish powder under his gloves. Alyx was firing at something from the top of the ridge, then she leapt down into a culvert holding a thin stream of acid. Gordon splashed in after her, thinking he saw silhouetted figures on the far side—wondering if they had seen him. Alyx moved quietly up the gulley, but as Gordon followed he heard movement behind them. Tall shapes, gleaming armor, bristling with weapons, appeared on the edge of the ravine. So much for the advantage of height. Alyx noticed them at the same time he did.
  "Shit," she whispered. "Combine Elite."
  They looked like metal, but their movements were muffled, almost silent Gordon never heard the squad that had dropped into the culvert ahead of them. All he knew was that suddenly they were surrounded....