She half-dragged Capicza the first dozen meters until he managed to get his feet under him. Then they were sprinting through a shooting gallery as the rapids of the River unleashed themselves on the plateau.

Ivy was too stunned and terrified to take in more than fragments of the unfolding battle. She caught glimpses of Scraegans bulldozing their way through the human defensive perimeter. Furnace blasts screamed back and forth – the Alpha from the dig site slew one of the interlopers with a pulverising blow of its immense axe, painting the plateau with dark blood.

Then her earpiece erupted.

"All hands, immediate evacuation! I repeat, immediate evacuation! Implement emergency protocols!"

She dimly recognised the voice of the Blackwater sergeant, McKaine, his voice charged with fear even as he tried to give orders.

"All guard units, heavy weapon deployment authorised. Suppressing perimeter fire-"

The comm went dead.

"Emergency protocols?!" Capicza squealed. "What in bloody Rivers is that gonna do for us now?!"

"Just keep going!" she screamed back, pelting away from the fast-expanding epicentre of the battle. The protocols were straightforward enough: get to one of the emergency slip tunnels dug by the engineers when they first arrived here. The narrow passages had been intended for use if the plateau became geologically unstable, but right now they were all she and the others had.

Somehow Kelso's Blackwaters were keeping their composure through the mayhem. Several of them passed her, moving in the opposite direction, faces obscured by blackglass helmet plates and carrying all manner of heavy personal firearms from anti-armour rifles, to rocket and grenade launchers.

One of the tents nearby suddenly broke open, its sides fall outward propelled by a series of small explosive charges. Her eyes widened when she saw what it had been hiding.

A double-barrelled turret sat there, like those she normally saw bolted to the deck of Scout Cadre skiff. A pair of grim-faced Blackwater soldiers manned it, and as soon as the tent sides fell the weapon began traversing. Then it thundered into life, pumping shots into the enemy Scraegans.

That thought jolted her. Now they had friend and foe among the Scraegans?

One of the fire-furred brutes went down under a ferocious salvo from the Blackwater cannon, before two furnace cannons rounds came screeching out of the smoke and blew the gun – and its crew – to pieces. The debris flew in all directions and a secondary explosion almost knocked her off her feet as the ammo cache went up.

A triumphant roar erupted in the air.

Close by.

Too, too close.

Ivy turned and a whimper of terror slipped out of her mouth at the sight of a towering shape emerging from the smoke. The Scraegan's head lowered, teeth bared in a snarl, and it let out a roar so deep that her ribs shook and she barely felt like she could breath. She staggered backwards into Capicza.

"Oh, Everflowing..." he managed to gasp as the warrior raised its huge, blunt club, ready to pound them into mulch.

Something exploded in the Scraegans face before the blow could land.

A flare of light erupted from the detonation that stung her vision and she had to shield her eyes with a curse. A phosphorus grenade – fired right into the monster's teeth. The warrior went reeling backwards, bellowing in anger and clawing at its eyes, and when Ivy could focus again, she saw a familiar figure come limping out of the smoke.

"Ivy?!"

Kelso. She couldn't form any words, fear still constricting her throat.

"Are you alright?" He shuffled forwards, his left leg barely bending as he lurched awkwardly in her direction. In his hands he carried a big, drum-loaded grenade launcher, with a fat barrel about the width of a jam jar. His body armour was burnt and scraped, and she could see wisps of smoke coming off of him,

Ivy managed to nod.

"You okay, sir?" Capicza blurted shrilly, glancing at Kelso's leg.

"I'll live." Kelso pumped the gun's loader and took aim, firing a second phosphorus grenade at the reeling Scraegan. Another blinding flare seared across her vision, then Kelso had her by the shoulder. "Let's go! To the tunnels!"

Following his shambling gait, she stumbled on through the bloodshed. It seemed like the whole world was on fire – screams assaulted her ears and for a moment she was transported back to Ozzmar, back to her first encounter with the hideous Crawlers.

Ivy felt her lungs constricting. She'd seen hideous things that day, and those memories came rushing vengefully back into her brain. Bodies disappeared beneath those limbs and maws and thrashing tails. People dying in ways no-one deserved.

"Shanklin!"

The shout yanked her out of that place, then she felt a hard shunt against her shoulder that sent her flying. There was a sudden, fearsome heat, a scream, and then an explosion that flipped her head over heels. For a moment she was weightless. Then she slammed down into the stone of the plateau again, scraping her face across the rocks and jarring her shoulder.

Rolling with the impact, Ivy came to her knees, shaking her head and blinking to try and clear her swimming vision. Agony throbbed along the right side of her head, and she could feel a twang in her shoulder where something had been pitched out of joint. Her ears were ringing.

Furnace cannon. Had to have been. The air around her was virtually sizzling with the heat, creating a haze that it was hard to see through. She looked around in a daze, picking out muddy shapes in the chaos. Then her eyes fell upon a dark smear lying nearby.

It took a few seconds for her to fully focus, and when she did her heart lurched.

"Capicza!" Ivy screamed in horror, scrambling on all fours over to where he lay. His engineers' overalls were still smoking from the blast, and when she turned him over, a sob choked her throat.

The whole right side of his body was a ruin of cauterized flesh. She could see licking flames and the sickening white of bone where his skin and muscle had been melted away. Then the smell hit her and she vomited there and then, unable to stop herself. Hacking out a cough and wiping away tears, she shook him feebly.

"Capicza, c'mon," she wheezed, but it was just a reflex. He was already dead – eyes staring sightlessly up at the roof of the cavern. She let out a scream that mangled together all the fear, shock and rage in one go and slumped back into a sitting position, acrid smoke washing over her battered frame.

Ivy was still coughing and spluttering when a firm hand grabbed the collar of her engineering harness and dragged her to her feet. She stumbled and turned to find Kelso there, his face tight with pain, his left legging dragging behind him like an anvil.

"He's gone, Ivy!" he shouted into her face. "We have to go!"

And she knew he was right. Spitting and wiping her mouth, she cast one last bitter glance at Capicza's corpse and then nodded. She quickly took his right arm over her shoulder to help support him, and together they set off at an awkward hopping run towards one of the emergency slip tunnels.

They made it about twenty feet before a screaming furnace cannon blast smashed into the tunnel mouth and caved it in. Ivy jerked to a halt, her breath catching in her throat as several small bodies tumbled down towards Rychter's lava flows. Some of them might survive in the netting, if it hadn't been dislodged by the fighting, but she had a grim feeling that that would be a mere stay of execution for those unfortunate souls.

They juddered to a halt and Ivy looked around frantically. There were other tunnels, but she doubted they could run the gauntlet in time. Even if they could, there was no guarantee they'd have any more luck.

So this is it? Ivy ground her teeth together in frustration. They'd found so much here, but still barely scratched the surface. And now it was all about to be turn away from her, just when she thought they were starting to unravel the mystery. She looked at Kelso, but his face was twisted with indecision, his jaw tight and veins throbbing in his neck as he tried to ignore the pain of his injuries.

He didn't know what to do.

She moved away from the edge, fighting to keep her feet as an ominous rumbling passed through the rocks beneath her. This place was unstable enough without two groups of Scraegans annihilating each other on top of it. Ivy tried to think, her eyes roving in all directions.

Then she saw one of the guidelines, still fixed in place, leading right out across the plateau. Her eyes lit up. It was probably insane, but right now they didn't have a whole lot of options.

"The dig site!" Ivy blurted, a faint glimmer of hope igniting in her mind.

"What?!"

"The stuff it's made from ought to keep us safe from any blasts," she yelled, forcibly turning him. "C'mon, sir!"

Kelso wasn't in any position to argue. The plateau was getting torn to pieces. Scraegans were slaughtering each other all around them and most of the humans that hadn't reached the escape tunnels were already dead. Guard posts went up in flames as the Blackwaters sold their lives dearly, but there was no fighting their way out of this.

They hobbled their way over to the pulley, and Ivy quickly fastened her harness to the shuddering guideline wire, fumbling with shaking hands and swearing wildly until she got it in place. Kelso looked out and swallowed hard.

"The netting's gone," he informed her.

"That's a chance we're going to have to take," she shot back with a lot more bravado than she felt. Then she risked a glance over the edge and wished she hadn't. Nothing to break their fall except a river of fire.

Ivy looked back over her shoulder, the encampment now completely up in flames. Scraegans still crashed through the smoke, blasting and bludgeoning at each other. Her gaze snagged on two figures bigger than the others.

The leader of the attackers had the Scraegan Alpha on its knees, its stone club gripped in both huge paws. It raised the weapon high and uttered a stream of something in the Scraegan tongue, before it brought the hammer crashing down on the top of the Alpha's skull.

Seeing their one time ally pitch forward, dead, was enough for Ivy to gather her nerves.

"GO!" she screamed, grabbing hold of Kelso and looping a guide wire through his the straps of his armour. Then she kicked wound the pulley system and kicked off into empty space.

The heat from below was immediate and she cranked the pulley as fast as she dared. She could feel the line wobbling violently and knew it wouldn't hold for long under the strain. They probably had thirty seconds to get across the gorge.

"C'mon," she snarled through gritted teeth, seeing the dark recess of the tunnel grow tantalisingly close.

Suddenly they dropped.

A scream whipped out of her throat when she thought they were dead, but they only fell a few feet, the line slackening, then evening out.

"We're okay!" Kelso yelped, even his composed demeanour finally evaporating. "Keep going, keep going!"

So she did. Her hands moved like a windmill as she hauled them closer and closer, until at last she was close enough to stick out a foot and catch the edge of the tunnel mouth. With a shriek of effort she hauled herself and Kelso onto solid ground.

"Unhook!" she shouted, pawing wildly at her own harness. The metal clips came free, just as the guideline snapped loose from the cavern wall.

It pulled her forward. Her mouth opened for another scream when she almost pitched over the edge.

Kelso grabbed her and yanked her back, and they both collapsed into the darkness of the tunnel. She went rigid for a moment, not quite believing that she was still alive. Then she went limp with relief and clamped her hands over her eyes.

"You alright?" Kelso coughed after a moment.

"I think so." She sat up with a groan, massaging her shoulder. Her head still ached, but there didn't seem to be anything broken.

"Bloody Everflowing – Shanklin, that you?"

She almost jumped out of her skin at the sound of Captain Kenyatta's voice. Ivy scrambled to her feet and whirled around to find Kenyatta and two other engineers with torches.

"Yeah... yeah, it's me," she managed, then gestured to Kelso. "Me and Specialist Vannigan."

"Captain," Kelso grunted. "Don't supposed one of you ... fine people might ... help me up?" He gestured to his injured leg with a smile of gritted teeth.

"Get him," Kenyatta ordered, and beckoned Ivy. "C'mon, we need to get out of sight."

"Did anybody else make it over?" Ivy asked as she stumbled into line behind her captain.

"A couple who were already at the guide station," Kenyatta answered grimly. "But most of our people tried for the tunnels. Some of them made it. Some of them..." She didn't bother finishing the sentence, and instead glanced back. "Capicza?"

Ivy felt a lump in her throat, and shook her head. "He didn't make it." For a moment she couldn't get the words out, the memory of Capicza's face still raw in her mind. After a moment she forced herself to say it, and added, "he saved my life."

"He was a good man." Anger sharpened Kenyatta's words.

The sound of battle echoing through the passage deadened any further conversation, and they followed Kenyatta through the narrow defile and back into the alien outpost, its black walls closing in oppressively around them.

They made their way into the control room in the bowels of the complex, where they found maybe twenty people, mostly engineers and technicians, and a quartet of Blackwater troopers who by sheer blind luck had been assigned here as security. No-one spoke as the rumbling of conflict continued, and Ivy sank down against one of the support pillars, just listening. Feeling the faint vibrations in the black stone-metal.

When the silence came it didn't make her feel any better. Ivy rubbed her stinging eyes with both hands and waited, still listening.

"Captain," Kelso whispered eventually. "The Scraegans left alive out there are not our friends. I'm not sure how much they know about this place, but we'd better not draw attention to ourselves."

"Lights!" Kenyatta hissed, making a chopping motion to the other survivors.

A minute later the torches and temporary work lights died one by one, plunging them all into darkness, save for the eerie blue glow from the facility's power lines. Ivy could just make out shapes in the gloom, but no faces – just vague shadowy outlines.

"Now what do we do?" she asked quietly.

"We sit tight," Kelso replied.

Kenyatta snorted. "We can't stay here for long, specialist. We've got no real weapons, a handful of rations and a few canteens of water."

"I know that. We got a distress call off before the comms tent went up," he told her. "And I have it on good authority that there's a relief force already on its way."

"There is?"

"Oh, yes." She could almost hear his smile in the darkness. "And if everything goes to plan, they should be here in less than two days."

"How in the Everflowing are they sending a relief force?" one of the guards asked. "Sir, the Scraegans are on war footing everywhere else on this planet."

"Because they've sent one person who knows how to cooperate with the Scraegans better than most."

Ivy felt her heart leap and she straightened up. "Ryke?!"

"Yes, Ivy. My brother's on his way, and he's not coming alone."