WEATHER CONTROL
  The first they knew of the Combine's arrival was a distant roar. Gordon looked to the sky, clearer now than it had been since his arrival, the thready strands of greenish vapor finally receding, actual sunlight beginning to strike through. The canyons of ice through which they steered the battered Bradleys threatened the first faint glimmerings of glare; he'd need sunglasses soon if it kept on like this.
  But with the heart-lifting glimpse of the sky came the reminder of death—more of a promise than a reminder.
  Slicing through the mists, so high that at first he thought them birds, came a swarm of ships. Light, swift aircraft passed across his vision long seconds before he heard the shock of their passage. The clouds swallowed them up. For a moment all was still. The Bradleys rumbled on, but the soldiers, Vance's men, grew silent and shifted their grips on their weapons.
  A second later, they were engulfed in an explosion of ice. A canyon wall blew into glittering shards. Gordon saw the Bradley nearest to the wall hurled spinning across their path; it sank head-on into the opposite wall. Another explosion, this one somewhere behind, deafened him.
  He could see the soldiers shouting, but heard nothing but the ringing. He knelt instinctively, trying to find some protection, and as he did he saw another of the Combine airships sweep low over the canyon, directly overhead. Something hit the ice in front of them. The men who noticed hurled themselves out of the back of the Bradley, as if the vehicle itself might offer cover. Gordon flung himself to the snow, and then was flung by the force of the blast.
  When he regained his senses, he saw the other men struggling to free themselves from the mounded snow. A few did not move. Up ahead, a grayish figure covered in ice made a bold gesture, beckoning them forward. The soldiers staggered forward, as the surviving Bradleys continued to rumble up the canyon toward their destination. He caught a glimpse of Alyx's face in the back of the rearmost Bradley, and was surprised by the sense of relief that touched him then.
  Tensed against further strikes from above, Gordon scrambled toward the ice-covered soldier. As he drew closer, he saw it was Vance himself, rallying the men, shouting orders he could barely hear. But the squad seemed to know what to do. Spread out across the width of the canyon, they hurried on, skidding and sliding on the ice. The canyon opened out, and around the next bend Gordon got his first sight of the Weather Station.
  It was a low dome, jutting with antennae and radar dishes, tiny red lights blinking above them. Around the dome were more structures, built low and painted white, almost indistinguishable from their surroundings. The whole thing was sprinkled with snow, like powdered sugar, but it was hardly a pristine image. There had already been fighting here. Smoke rose from a crack in the dome. The soldiers stationed inside the station had massed against the Combine operators as the news of the uprising spread; the fighting had torn it apart from within.
  Vance caught sight of Gordon, grabbed him by the arm, and thrust his craggy face close to Gordon's ear: "There's a cargo plane coming for you, Freeman, but god only knows how long it'll take to get here—if it makes it through at all. Once we get you aboard, you can take those chips back to City 17. But we've got to last that long. We'll hold off the Combine as long as we can from out here, then well fall back into the Weather Station. I'm not anxious to get holed up in there, sitting targets, but we're awfully damn exposed out here."
  As if to underline his words, a shadow fell over them. Gordon looked up to see an enormous ship crest the edge of the canyon, so close that it seemed to be crawling across the ice.
  "Jesus, that's a mech carrier," Vance said. "I didn't think they'd be here this soon. Get moving!"
  To Gordon's horror, the carrier drifted to a spot between him and the Weather Station. He expected it to settle on the ice, blocking their route completely. Instead, a hatch gaped in its belly, and a huge metallic parcel was lowered to the snow. As the carrier lifted, the package opened itself, metal unfolding into a nightmare that by now had grown familiar. It was a mech, one of the same that had chased him across the wasteland and harried him and Alyx. It was a cousin to Eli's robot, Dog, but apparently new-minted, and still without blemish; there was nothing awkward or hesitant about its first steps.
  Gordon stared at the thing in something like awe, but the soldiers shared none of his wonder. They had seen the mechs many times, perhaps even fought alongside them; but never before had they fought against one. Still, they didn't hesitate. As if they had rehearsed exactly such an encounter, they moved into defensive positions. Each man seemed to know his role. Gordon began firing at the metal shell of the thing, but without much sense of its weaknesses—if it had any. But the soldiers were more methodical. The mech began targeting them, neatly pruning men from the unit, but for every soldier it killed, another one seemed to advance further in the unit's plan.
  Gordon's pulse quickened when he spotted Alyx down there, in the fray. She had leapt from one of the Bradleys while the others sped on toward the Weather Station, and she was coming up on the mech from behind. She had a grenade out, primed, ready to throw. Vance shouted something and ran straight for her, and his cry must have distracted her—for the grenade went wide, exploding in mid-air to one side of the mech's "head."
  The thing stopped, judging this explosive more of a threat than anything the soldiers carried, and began to pivot its heavy head to bear on Alyx. Gordon might have shouted something himself, but he was aware of nothing but Alyx standing there, looking suddenly so small, so alone, the brightest possible target in all that ice. He was running, firing helplessly at the shining carapace, running like Vance toward his daughter.
  The mech's head did something, it pulsed with a faint glow as if powering up for a particularly lethal strike. One of the gun barrels swung toward Alyx, who backed away in atypical shock, as if she couldn't believe her throw had gone so wrong.
  The mech began to fire, but in that instant its entire upper carapace exploded.
  Gordon saw smoke rising from the direction of the Weather Station, trailing from the barrel of a huge gun located on the field below the dome. The blast had thrown sheets of accumulated ice from an installation of antiaircraft weapons. And now other guns began to spit fire and missiles as the men from the Bradleys leapt into the bunkers and began to take on the airships.
  Alyx had fallen, but by the time Gordon reached her she had regained her feet, with Captain Vance helping her up. She gave them both a brief flicker of a smile, then shrugged toward the guns. "They're going to need our help up there." She started running. She was still running when the next wave of shadows swept over the canyon, and the Combine forces—not merely advance guard—arrived in earnest.