Sawyer secured the straps of Julia’s helmet under her chin and pressed his lips to hers. Her eyes were wide and her breathing shallow.

“I’ve got your back. We’re going to be fine. Just do as I say.”

She nudged him in the ribs. “Right.” But the glimmer of a smile touched her lips. She straightened her back. “I’m good.”

He checked their weapons and supplies before they continued down the rapidly narrowing tunnel. They had two packs filled with undamaged explosives. They could still do this.

Sawyer took the lead, Julia bumping on his heels but he didn’t mind. He wanted her close, where he could protect her. Claustrophobia pressed against his mind as the ceiling loomed lower and lower. Eventually, he had to bend to keep moving.

“Holy shit.” The tunnel extended forever, a relentless midnight shaft broken only by their labored breathing. The water level dropped until it was only sloshing against the soles of his boots, leaving the wet fabric of his trousers chafing his legs.

He stopped and listened, slowing his breath, one hand stretched behind him to stop Julia without words. The murmur of water was loud, but his ears had detected something else. The hairs on his forearms prickled, and he had the inexplicable sense of being observed.

“What?” she asked.

“Thought I heard something.” His headlamp beam swept over curved, swooping alien scales.

Sawyer cocked his head. He could feel it and hear it. He wasn’t sure, but it was there, the maleficent hum from earlier. Swallowing his distaste, he flattened his hand on the side of the tunnel, wanting to be wrong, but also needing to be sure. With his palm flat, it was even more obvious, a thrumming through the flesh of his hand. He turned to see Julia doing the same.

She glanced up at him and smiled, but there was a sheen of perspiration on her brow and tight tension hunching her shoulders. She licked her lips and murmured, “Nearly there.”

The tunnel widened and he was able to inch forward, Julia at his side, the Sweeper held in front of her like a protective talisman. Bright dots indicated the presence of the Chittrix, dominating more than three-quarters of the Sweeper’s monitor.

Julia inclined her head in the direction of the screen. “It’s big. They must have excavated tons of earth.” She shook her head, agitated. “I have no idea how we haven’t spotted the earth removal.”

“Maybe they dumped it in the river?” Sawyer crept forward, light from his pulse rifle dancing. He followed the beam with slow, cautious movements. Under his feet, the ground began to angle downward, subtly at first, and then his thighs were resisting the slope, straining to keep him upright. The angle urged them on as the ceiling slanted increasingly lower, forcing Sawyer to walk with his head flexed forward. His neck muscles were aching almost as much as his protesting thighs.

“Distance?”

“Less than fifty feet,” Julia answered, her own head only a few inches from the tunnel roof.

Encrustation surrounded Sawyer from all angles, permeating his pores with alien molecules. Was there ever a time before the Chittrix? It was becoming difficult to remember.

“We’ll start planting charges here and work our way forward, as close to the nest as we can get.” He rolled his backpack from his shoulders, dropped to his knees, and unpacked the top layers of TNT.

Julia hovered close by, scanning with the Sweeper as he worked quickly. He prepared the charges for detonation as Foster had shown him, before jamming them in crevices and splits in the wall.

“Sawyer, how are we getting out?” Julia asked in a small voice.

He hesitated, his hands resting on a charge as he gathered his thoughts. “Forward. If we can’t go back, we go straight through.” He stretched and stood, ignoring his throbbing knees and wrapped his arms around her from behind. He buried his face in her soft neck. “We can do this.” She slid her hand on top of his and locked their fingers together.

The warmth of her hands focused his mind. On the fight. On protecting Julia. He knew then he was willing to sacrifice everything to make sure she survived. He released her and shot her a reassuring smile as he shouldered his pack and moved off again, deeper into the tunnel.

They continued to descend, gradually losing any sense of where they were spatially. Sawyer was completely disorientated beyond the fact that the Chittrix nest was now in their direct path, and it took him by surprise when the passageway widened into an open space. Cool air bathed his face, surprising his yammering heart. He dipped low, sliding in behind peppery-colored granite rocks, chilled sweat pooling in the small of his back.

The path they had been following fell steeply down a sheer cliff of rubble, tumbling down to a vast underwater cavern. Above, the rock curved into a vaulted ceiling of dizzying proportions, tapering to a point sixty feet above Sawyer’s head, red brick still visible in places. Shards of light splintered through hairline openings from the world above, highlighting soft winks of granite and quartz scattered through the gloom.

Julia scooted up beside him as he did a mental reconnaissance of the area.

“This cavern looks like a mix of man-made and Chittrix.”

“Just like Darr said.” Julia whispered. “Maybe he’s not all bad.”

Below them, a large underground lake extended from one side of the cavern to the other, circled by a narrow ledge of rock. A sleek Chittrix carved across the water like an alien whale, waves curling from its sides as it plunged effortlessly under the water in a hushed dive.

Sawyer wiped clammy hands on his thighs, hairs lifting on the nape of his neck. He concentrated on the sensations. Fear would keep them both alive.

Julia pointed, drawing his attention. On the lower extent of the walls, close to the waterline, Chittrix curled into crevices, their enormous, hooked talons securing them to the rock wall. Their lethal tails hung twitching, constantly swiping through the water. Sawyer was reminded of fish, fanning their eggs to supply them with fresh oxygen. He pulled his weapon sights from his belt and scanned below the ledge. The world wavered in and out of focus, water lapping at the rock wall. Finally, he spotted the top edge of ebony honeycomb, dark shapes shifting behind the faceted structures.

Egg chambers, half-submerged.

Sawyer dropped his backpack onto the rock beside him. He quickly unpacked climbing rope. “This is our best chance.”

Julia unhooked the Sweeper and cricked her neck. “What?”

“We go down and plant the explosive.” He pressed a thick silver anchor and small rock hammer into her palms before cupping her small hands against his lips in a kiss.

“Do you trust me?” he asked.

She didn’t hesitate. “Absolutely.”

“Secure this anchor into a crevice or split in the rock back from the edge while I sort out the rope.” He pushed his pulse rifle onto his back so he could work freely, winding the rope in giant loops from his elbow to his shoulder so it would uncoil without knotting.

Julia shuffled on her backside away from the edge, her fingers searching the debris-strewn surface for a crack. She glanced up at him. “Sawyer, there are so many down there. A whole nest.”

“Yes. We can do this. Trust me.” He smiled. It was down to him now. He had to get her out of here in one piece and bring her home. Sawyer touched the explosives in his backpack. “There’s enough to seal this cavern off for good, if we get the charges in the right place.”

She nodded, her mouth thinning to a determined line. “Let’s get to work.”