by Troy Denning
A message appeared on his HUD: CO2 12% CH4 3%
Carbon dioxide and methane. Neither was breathable, and methane’s explosive properties could make it instantly fatal.
“No sparks,” John ordered, both over TEAMCOM and through his voicemitter. “I’m detecting high levels of methane.”
The percentages climbed rapidly as he continued forward, the carbon dioxide now at 17 percent and the methane at 7 percent. At least he understood why they hadn’t blown up yet. There wasn’t enough oxygen in the air to support an explosion.
But methane could still burn at those levels.
John reached the LHD and slipped alongside it, then pulled Mukai’s unconscious form back in her seat and killed the engine. The carbon dioxide levels had topped out at 21 percent, but the methane was at 12 percent and still climbing.
“Evacuate down the—”
“Too late,” Fred said. “The rangers are down.”
“Might I inquire as to what the hell happened?” Kelly asked.
“Bad air.” John pressed the pad of his left ring finger to Mukai’s throat. The sensor activated, and her pulse rate appeared on his HUD—a frantic 120 beats a minute. “We need ventilation. Now.”
John pulled the MA40 off its magmount and fitted the sound suppressor onto the barrel, then began to fire—quietly—at the ceiling, his rounds chipping away at the meter-thick lechatelierite. Even with so much carbon dioxide in the air, there was still a slim chance that a gunshot would ignite the methane and cause a flash fire. But for Mukai and the rangers to pass out so quickly, the oxygen levels had to be almost nothing, and methane couldn’t burn without it.
And if he was wrong—well… Mukai and the rangers wouldn’t be any more dead than if he’d let the bad air asphyxiate them.
He continued to fire—it took a lot of kinetic energy to punch through a meter of ash-impregnated lechatelierite—creating a half-meter circle of weakened glass directly over the rear engine compartment of the little LHD. Down the passage, he glimpsed Kelly firing her own sound-suppressed MA40 into the ceiling. Once he had emptied the magazine, he climbed onto the back of the machine and rolled onto his back, then began to punch.
It took three blows to create a hole to the surface, and the carbon dioxide and methane readings in his HUD began to fall immediately. He unbuckled the safety harness holding Mukai on the operator’s seat, raised her night-vision visor and pulled the helmet off her head, then pushed her up into the hole, just high enough that her head would not protrude above the surface.
As he waited for her to recover, he looked back to find Fred and Linda starting down the passage with two Reavians slung over each shoulder. They were dragging four more by the wrists, but they would never be able to get everyone out of the bad air in time. John could see at least fifty rangers lying in front of alcoves down the way, and more people were dropping as the foul air moved down the tunnel.
Kelly was using the butt of her assault rifle to punch through a circle of lechatelierite she had weakened. Her hole and John’s would help reduce the methane levels, since it was lighter than oxygen. But carbon dioxide was heavier, so the makeshift ventilation would only dilute the bad air. Elevated levels were going to continue being a problem as long as there was gas coming out of the pocket ahead.
Mukai returned to consciousness with a startled gasp. She began to mutter and babble, trying to make sense of her sudden detour into oblivion.
“Whatever you do,” John said, “don’t scream.”
“I wasn’t planning on it,” Mukai muttered. “Am I going to want to?”
“Not sure yet,” John replied. “You hit a pocket of bad air. I haven’t had time to assess.”
Mukai got her legs under her, placing her boots on John’s chest, then looked down with a blank stare and whispered into the darkness, “Am I standing on you?”
“For now,” John said. “We’re on the LHD’s engine compartment. When you’re feeling steady enough, I’ll slip out from beneath you.”
“I’m okay,” Mukai said, still whispering. She picked up one foot and began to feel for the engine hood. “But I can’t see a damn thing down there.”
“Sorry about that,” John said. “I need you to watch the base. We’ve fired a lot of ammunition down here, and that glass over our heads isn’t so thick that an enemy lookout couldn’t have noticed something.”
“I can do that,” Mukai said. “But my natural night vision isn’t something I’ve ever bragged about.”
“I’ll pass your helmet and visor up to you,” John said. “Just be careful not to stick the helmet too far above the surface.”
“You think?” Mukai said. “I can see the top of the shield barrier from in here. It’s right there. I mean, in grenade range—for me.”
“Understood.”
John guided her boot onto the hood next to him. He waited until she had shifted her weight to it, then slid out from beneath her other foot and swung himself back onto the tunnel floor. Mukai gave another startled gasp as the LHD springs decompressed and lifted her twenty centimeters higher into the hole.
John grabbed the helmet from the operator’s seat and passed it up, then changed the MA40’s magazine and returned it to its magmount. He slipped forward alongside the LHD and peered through the hole it had punched through the working face of the tunnel.
Now that he was closer, his night-vision system was no longer being compromised by the heat of the LHD engine, and the dimdots were visible along the edges of the passage. He could see the faint red glow of the Banished shield barrier overhead, shining down through a circle of lechatelierite thirty meters in diameter. A three-meter band of crimson cracks ran down the center, where something heavy had driven across it and nearly collapsed the entire span of glass.
The gas readings on John’s HUD shot up to 27 percent for the carbon dioxide and 14 percent for the methane. He had his onboard computer check the oxygen level, which was only 5 percent—less than a third of normal. At those levels, he wasn’t sure whether methane could burn.
The answer appeared on his HUD, informing him that it could not. So at least they had that going for them.
When John tried to scan the rest of the chamber, it took a moment for his night vision to adjust—and when it did, he found himself looking across a shallow basin filled with hundreds of rotted trees. The trunks lay next to and atop each other, all running parallel as though they had been blown over by the same powerful wind. Everything was blanketed in mold, sometimes so thickly the trees seemed to have all dissolved into a single amorphous mass, and there was so much humidity in the air that it quickly formed droplets and ran down his faceplate.
He grabbed a chunk of lechatelierite from the passage floor and tossed it into the basin. The mass didn’t ripple—it was more of a shudder—but at least he knew where the bad air was coming from. Bogs produced a lot of carbon dioxide and methane, and it had all been trapped underglass until Mukai opened the pocket.
Over TEAMCOM, John said, “We’ve hit an obstacle.”
“I’d say it’s more like a titanium wall,” Fred said. “The bad air is moving faster than we are. The tunnel back here is paved with unconscious soldiers.”
“Understood,” John said. “Lieutenant Chapov, are you and Major Van Houte still with us?”
“Affirmative.” Chapov was with the drilling jumbo back at the erosion channel, almost a kilometer distant. “Should we start the drills and cut away the ceiling?”
“Negative. Use your head.” John spoke more harshly than was really necessary, but he was not accustomed to having to tell mission personnel what not to do. “What are you thinking?”
“That you need fresh air in that tunnel—and fast.”
“Not if it means flashing a big blue HERE WE ARE sign along the attack route,” Fred said. “This fight is going to be tough enough already.”
“You’re still planning to attack?” Chapov asked. “Without the rangers?”
“Withdrawing isn’t an option, Li
eutenant,” John said. “For anyone.”
The Banished had entered the militia’s underglass tunnel network two days ago, and they were not being subtle about taking control of it. Whenever they ran into a pocket of resistance, they simply brought in a Griever fighter-bomber to turn the pocket into a crater. So if the rehab pioneers wanted to survive until the Infinity’s marine complement arrived to relieve them, they needed to capture the New Mohács armory and establish some anti-aircraft emplacements on the surface.
Chapov didn’t answer for a few heartbeats, perhaps chastened by John’s sharpness, then said, “Sorry for not seeing that, Master Chief.” The hum of a transmission engaging sounded in the background. “Carbon dioxide needs a place to sink. I’ll look for some big bedrock fractures in the floor and open them up. Maybe we’ll even get lucky and hit a cavity.”
“Good plan,” John said. “But stay back from the contact zone. You’re not going to save anybody by going down yourself.”
“Affirmative.” It was Van Houte who said this. “No need to worry about us, Master Chief. I’m enough of a coward for both of us.”
“Glad to hear it, Major.” John could not help smiling inside his helmet—Van Houte was anything but. “Blue Team, you’re with me, and bring all the rangers you can carry. We’re crossing the—”
“Check that,” Mukai said. She dropped her head out of the ventilation hole, her head and eyes still obscured by her helmet and night-vision visor. “We have a sentry squad…”
She started to wobble, then tumbled off the LHD into the wet sand. John grabbed his MA40 off its magmount, stepped over her, and squatted on the back of the LHD with the barrel pointed into the ventilation hole.
He could hear Kig-Yar approaching, chattering to one another in barely lowered voices. It sounded like there were five of them, which was going to be a problem. The hole was only large enough for two of them to look into at once—which meant he could only shoot two at a time. He laid the MA40 on the LHD hood so both hands would be free.
A moment later, the blue glow of a personal lamp began to travel back and forth through the lechatelierite, then slid into the ventilation hole and stopped. A Kig-Yar chortled in excitement, and the beam began to descend the wall of the opening.
John waited until two beaked heads appeared above him, one peering over each side, then reached up with both hands and grabbed their necks. He pulled the one holding the lamp into the hole first, allowing it to drop squealing to the passage floor, then jerked the other one down after its companion.
The other three squawked in surprise, but John already had his sound-suppressed MA40 in hand and was pushing it up out of the ventilation hole. He turned the barrel toward the most distinct voice and fired a short burst. It sounded like someone coughing. As he continued to rise, he swept the barrel in the opposite direction, toward the other voices, and fired a longer burst.
When he stuck his head out of the hole, three Kig-Yar were lying motionless on the glass, their pooling blood glowing white in the infrared mode of his night-vision system. He took a moment to scan the surrounding area, searching for more sentries or some sign that these five had been under observation, but saw only the radiance of the shield barrier looming twenty meters away. A lookout tower stood fifty meters away in either direction, but the Unggoy sentries seemed to be watching the horizon rather than the perimeter patrol—a common mistake that hinted at complacency. Had the Banished been expecting an attack, one of the tower sentries would have been watching to see if the Kig-Yar patrol ran into trouble.
Not that it mattered. When the patrol didn’t report, a larger one would be sent to check on it, and the base would go on alert. Blue Team and the rangers had maybe ten minutes before that happened.
John pulled the three bodies down through the hole, then looked down to find Kelly checking to make sure they were really dead. She had already put a round through the heads of the first two—special forces units rarely took prisoners, and they never left a live enemy behind themselves.
Linda and Fred stood behind Kelly, each carrying one ranger over each shoulder and another in their arms. John motioned to the LHD bucket.
“Load up. We’re going now.” He adjusted the LHD’s seat all the way back, then squeezed into the operator’s compartment. Backing the machine up a couple of meters, he dumped the bucket’s contents at the edge of the bog. “And don’t forget Chief Mukai.”
Kelly slipped alongside the LHD to the front, then began to take unconscious rangers from Fred and Linda and load them into the bucket, laying them on top of each other. John wondered how long had passed since Mukai had opened the pocket of bad air. A counter appeared on his HUD and began to run upward.
3:41… 3:42… 3:43…
Brain cells died at just one minute without oxygen. After three minutes, permanent damage could occur. After five minutes of no oxygen, there was no coming back—and the survivors wouldn’t be in any shape to fight.
Kelly stepped into the bog basin and moved away from the LHD, testing her footing before each step. Moss and wet sand squished up around her boots, but she didn’t sink more than a few centimeters. Maybe the LHD wouldn’t mire after all. John depressed the forward pedal, and the machine lurched out of the passage into the bog.
He felt the LHD settle and slow as the tires began to tear through rotten logs and fling sand.
3:55… 3:56… 3:57…
The LHD reached the middle of the basin and started to sink faster—then suddenly slid forward. He checked his motion sensor and saw the rest of Blue Team lined up behind the cargo platform in back, pushing against the haulage buckets and other equipment. He let off the pedal a bit so the tires would stop digging, but still kept them turning, and the LHD went the last dozen meters to the far side of the bog, where the basin dead-ended in a dirt slope similar to its counterpart on the other side.
John dumped Mukai and the rangers onto the slope where they would be out of the way, then backed up, moved over a few meters, and drove the bucket a meter and a half into the dirt.
4:20…
The air was still 5 percent oxygen, even in the bog pocket. That wasn’t much—humans normally breathed air that was 19 to 22 percent oxygen—but maybe it was enough to slow the brain damage Mukai and the pioneers had to be taking.
John backed up the LHD, emptied the bucket, then raced forward again, pushing it another meter and a half into the slope. He thought he should be beyond the shield barrier by now, which meant there would be no glass overhead. The rehab pioneers who’d built New Mohács had spent several months stripping all the lechatelierite from the ground inside the perimeter and using it in their buildings and pavement.
John glanced up as he reversed to empty the bucket—and saw a red glow in the dirt overhead. He was directly under the shield barrier now.
4:26… 4:27… 4:28…
He emptied the bucket again and advanced under the glowing barrier, pushed another meter and a half into the dirt. The plan had been to carefully dig ten meters past the shield barrier and open the wall of an old concrete storm sewer that had served old Mohács, then crawl through the sewer system and attack all corners of the armory at once.
4:34…
No time for that now. As John backed out of the short passage he had dug, he glanced over at Mukai and the six unconscious rangers. They still had their weapons and packs full of C10 cubes. They would be shell-shocked when they regained consciousness, but that was the normal condition of any soldier who had ever survived an artillery barrage.
John spoke over TEAMCOM. “Make ready.” He emptied the bucket. “Blue Three, you’re point—secure the breach point. Blue Two, find the Banished birds and break their wings. Blue Four, take out the tower guards, then drop the shield barrier. I’ll handle the armor.”
Militia recon scouts had started watching New Mohács long before Blue Team had inserted on Reach, so they had a pretty good idea of what they would find inside the base.
John started back into the passage.
>
Chapov’s voice sounded over TEAMCOM. “Wait, you’re attacking now?”
“Never say wait unless you mean it,” John said.
4:43… 4:44…
“Do you mean it, Lieutenant?”
“No—uh, sorry,” Chapov said. “I mean negative. Just surprised.”
“Don’t let it happen again.” John raised the bucket as high as it would go. “What’s the situation back there?”
“I found a cavity,” Chapov said. “Carbon dioxide levels must be dropping, because people aren’t passing out anymore.”
“Anyone waking up yet?”
“Negative.” It was Van Houte who said this. “I think we have at least three hundred incapacitated.”
Three hundred. Sixty percent out of the fight for now, and the enemy hadn’t fired a single plasma bolt yet.
“Everyone else is ready to resume the advance.” Chapov lowered his voice. “They’re not going to wait much longer. I’m telling you, these people are crazy.”
“Acknowledged. Shut down your plasma drills.” John depressed the forward pedal as far as it would go, and the LHD rocked back on its rear wheels as the bucket punched through the roof of the passage. “You’re about to get some fresh air, but the rise in oxygen levels may turn the methane combustible again.”
John lowered the bucket, bringing a cascade of dirt and glass block down with it, then slammed his heel down on the reverse pedal. The LHD shot backward into the bog. The rest of Blue Team slipped into the passage ahead of the machine, everyone holding silenced MA40s, and Fred carrying three packs filled with C10 charges over each shoulder. The trio disappeared briefly behind the bucket, then came back into view as they jumped up through the opening and into the base.
John heard the chuff of silenced weapons as they took out a few nearby aliens. He killed the LHD’s engine and climbed out of the operator’s compartment, then took a couple of seconds to strip the remaining demolition packs from the unconscious rangers and drag them and Chief Mukai under the opening. He wasn’t sure if the fresh air would do them any good, but the sooner it reached them, the better their chances of recovery.
