The Mammoth carrier trundled its way across the hard packed rocky desert, its vast, toothed tracks widely distributing its weight to stop them getting bogged down. Painted a pale, burnt orange, it blended into the sun-blasted landscape, a barely discernable cuboid dragging itself along the horizon towards their deployment zone. On the roof men and women from the scout infantry detachments sat in protective cupolas, massive anti-armour rifles scanning their surroundings for any sign of Scraegan activity.

They plunged headlong through sandstorms that would kill an unprotected human in minutes, the Mammoth's enormously thick plating proof against even the heavy ordnance of the Scraegan furnace cannons.

The Mammoth's hold could fit as many as forty Hunter-Killers if they were packed in tightly enough. Right now the thirty mechs of their attack force were arranged in two rings, one on top of the other, with a few meters of space between each. On the upper level, encased in the frame of his Hunter-Killer, Ryke waited with growing impatience. After all they'd done to get here, he couldn't help hating being stuck in the rear compartment of the transport, somehow no longer in control of his fate.

Directly opposite him the brassy mechs of Red Squadron stood, clamped in place at the waist by fat docking claws. On the level below, closest to the heavy rear access hatch, the veterans of HK-Bishop were arrayed, and it struck him how different the battle-hardened units appeared.

Somewhere beneath it all they'd started with the same burnished plates as the rookies, but now their hulls proudly bore scorch marks, blast scars and kill slashes, the sheen of the armour dulled by years of active duty in Rychter's unforgiving deserts. More than that, every mech bore a call sign emblazoned in thick, black print just below the bulbous head, names earned in active duty. He could see Parnell's machine near the front, the word 'HATCHET' gleaming more brightly than the surrounding armour plate. Hopefully one day he'd have his own battle-forged name on his own Hunter-Killer.

"All teams," Kelso's voice sounded through the Mammoth's internal tannoy, pulling him from his thoughts. "We are approaching deployment zone – ETA ten minutes."

Ryke rolled his head from side to side, loosening himself up before their deployment, trying to drill himself into treating as just another assignment, like any of Mulrough's training simulations. They could beat the simulations; they could beat the real thing too. He ran through his Hunter-Killer's systems on the HUD, checking them off one by one: armour integrity, power levels, weapon functionality, heat levels, ammo counters – all of them in the green. They'd been primed when they'd loaded onto the Mammoth in the first place, but some premonition forced him to check anyway.

Those final ten minutes crawled by and by the time they reached the deployment zone Ryke would feel his limbs trembling with excitement. He could feel the raw power of his Hunter-Killer just waiting to be unleashed. Ryke tried to keep calm, knowing he would need a clear head to give a good account of himself, even if their role was just support. His heart juddered as at last the Mammoth came to a halt, the shunt of breaking shaking him lightly in the harness.

Then the Mammoth's immense loading ramp disengaged. The slab of metal opened out from the back wall of the transport compartment, and hot light came spilling inside, until the door slammed to the ground, disgorging a small cloud of dust and pulverised rock. Then the waist clamps around the mechs of HK-Bishop disengaged.

He watched in fascination as the veteran unit lumbered from view, disappearing into the light in a two-by-two formation, the echoes of their heavy footfalls reverberating within the Mammoth like a bell.

"HK-Bishop to command," Parnell's voice cut through the comm. "We're clear. Commence phase two."

"Copy that," Kelso replied. "Squads Green and Red, prepare to deploy."

Kazem and Fallker sent their acknowledgements, and then it was happening. With a hiss of hydraulics and howl of motors the upper ring lowered until all twenty mechs had their feet on the ground. Then the waist clamps disengaged.

Squad Green led the way, moving in textbook formation with the nimble Raptor mechs leading the way. With Preese by his side Ryke took a deep breath and launched his Hunter-Killer into line, metal feet pounding metal decking as they loped into Rychter's badlands. Sunlight exploded over them as they cleared the dust cloud, but he tried not to get distracted by the massive shapes of the other Hunter-Killers, instead concentrating on the HUD to make sure he positioned correctly.

The Raptors peeled out in a pincer movement, just as they did in every deployment simulation they'd run, then the Riot mechs filled in the space between them at regular intervals. Last and by no means least the two Goliaths trudged out into the light, their immense cannons scanning for threats along their deployment zone. Behind them Squad Red mimicked them uncannily, wheeling to the right of the Mammoth.

"All teams deployed," Parnell said.

"Copy, target packages loaded to your HUDs," came Kelso's reply. An instant later Ryke's display flashed with a new target reticule.

"Alright, rookies, you know the drill," Parnell continued. "Take up defensive posture on approach to Alldeep. HK-Bishop, on me. We are moving into engagement zone. Standby for contact."

So far so good. Bracing, Ryke launched himself into a loping run as Green Squadron set off towards Alldeep, metal feet smashing up the hard-packed dirt as they went. He kept one eye on the HUD as he went, seeing Squad Red pull in behind them while the experienced pilots of HK-Bishop veered away, heading out onto open ground.

The town itself soon became visible to their left, the white of its buildings gleaming against the scorching suns, massive solar panels glinting in the light as they tracked the twins across the sky. Behind it loomed the massive, dark bulk of the Bronchite Ridge, an endless rocky spine that stretched away from left to right beyond the horizon. The settlement was built into it, a semi-circle of human habitation latched on like a leech. A low wall dotted with heavy cannons protected the outer edge, but they paled in comparison to the specimens that defended Brekka and Stamm Basin. A concentrated Scraegan assault would rip through them like paper – he knew that much.

On they pounded through the dust and grit, the thick armour of the Hunter-Killers impervious to the swirls and lashes of sundered rock that filled the badlands air. Ryke concentrated on keeping his spacing with the rest of his squad, keeping a partial eye on the ten drifting blips of HK-Bishop as they raced out to meet the coming Scraegan attack.

Squad Green's skirmish line looped to the far side of Alldeep's defences, before spreading out to fill in the gaps between the turret emplacements. He caught sight of small figures hunkering fearfully within their armoured cupolas. It must've been both worrying and encouraging in equal measure to see the formations of Hunter-Killers taking up station. Their deployment gave Alldeep its best chance at defence, but also confirmed the danger they were in.

They formed a secondary defensive ring, bulging out from the wall with the Goliath mechs pulled back nearer the wall. Massive hydraulic stabilisers unfolded like spider legs from their waists and pressed to the ground, anchoring the heavy Hunter-Killers in place so they could deliver salvos from their shoulder cannons with speed and accuracy that would be impossible under normal motion. With the recoil absorbed by the supports they could lob shells at will, and with devastating effect.

"Squad Green is in position," Kazem declared. A moment later Fallker confirmed that his unit had taken up its place. Then they had to wait. HK-Bishop were seeking the perfect fighting ground, looking to force the Scraegans to face them on the flat where there could be no collateral damage, and the much vaunted tactic of sheer mobility could be brought to bear in open space.

"Command to all units, hold station," Kelso said, observing proceedings from within the Mammoth's command cabin. "HK-Bishop, be advised we are tracking a Scraegan pack two clicks from your current position and closing fast. Commence deployment."

"Copy, command. Deploying charges."

Ryke licked dry lips, eyes flicking across his Hunter-Killer's readouts as they waited. The waiting. It was worse than being cooped up in the Mammoth. Now they stood primed, killing machines ready for war but with nothing to shoot at.

"Charges primed."

"Copy, HK-Bishop. Scraegan pack now one-point-three clicks and closing."

Seconds ticked by. Ryke tried to do the math in his head based on how quickly the Scraegans had covered the previous seven-hundred meters. It wouldn't be long before they were within the effective range of the mines.

"Detonating charges," Parnell said.

In the distance Ryke saw a line of geyser-like plumes of rock and rubble spew into the air as the seismic charges exploded, sending shockwaves reverberating through the flats that he felt even in the confines of his Hunter-Killer. Although the humans only had a limited understanding of how the Scraegans moved so easily underground, they had figured out that seismic disruption would interrupt that process. And bring their foes to the surface.

For a long moment nothing happened. His earpiece fizzed with low static and Ryke found he was holding his breath. Then in a rush time seemed to speed up as the results of the detonations became clear. He could see shambling forms just visible beyond the line of HK-Bishop's mechs, barrelling relentlessly through the debris.

"Ratchet to all teams, we have live, hostile targets – engaging!" Sergeant Parnell snapped crisply an instant later, as calm as she'd been back at Stamm Basin. "Squads Green and Red hold your positions – mop up anything that slips the net."

Kazem and Fallker sent their acknowledgments, and then all the rookie pilots could do was sit and wait. Ryke watched, hearing the hollow thump of explosions. Dust billowed on the horizon and he saw a dozen dark shapes churning through the clouds. The veterans had switched to their squad-wide band to keep their comms clear during active combat, so the supporting squads could only look on and hope. He found himself clenching and unclenching his fists in impatience, scanning the line of smoke for any kind of breakthrough.

"Looks like they're holding," Vela drawled. "And we got all dressed up and everything."

"Easy on the chatter, Vel," Kazem rebuked gently.

Ryke frowned. Although he only had a dim sight of the engagement beyond Alldeep's perimeter, it did seem odd that nothing and no-one had broken the thinly stretched line of HK-Bishop's mechs. The whole point of the rookies being there was that they'd expected to need some kind of support line. But here they stood, unneeded. Ryke itched to go racing out and help their comrades, and earn himself some kind of blooding in the eyes of the veterans, but discipline held him still. His chance would have to wait.

Then something exploded.

Something much closer.

Ryke had no idea what had happened, but the noise briefly overwhelmed his earpiece with a shrieking crackle. Thunder echoed across the barren plains as though a giant had clapped its hands, and a huge wave of grit rose up to flood out from the outer wall of Alldeep for half a kilometre in every direction. The shockwave shook Ryke's bones, his teeth rattling in his skull, and he had to spread the heavy-toed feet of his Hunter-Killer just to stay upright.

"Drown me!" he heard Preese curse. "What was that?!"

Ryke could only shake his head in bafflement as the shockwave subsided, leaving him to right himself, looking around at his fellow mechs. In the distance he could still see the milling forms of HK-Bishop facing off with the Scraegan attack force. He took an uncertain step forward, glancing down the line to see if anyone else had moved.

"Command, we just had a serious detonation," Kazem said, his voice uncharacteristically hesitant. "Can you confirm?"

"Confirmed," Kelso replied grimly. "Still looking for an epicentre-"

"THE RIDGE!" Thaye's shrill voice burst over the comm with a call that chilled Ryke to his core. "By the River, they're coming out of the damned ridge!"