The Chittrix twisted its thickly-scaled neck, tilting its head as it sensed easy prey. It loomed above Julia Simmons, ten feet of exquisitely evolved, alien killing machine, seven-foot barbed tail pounding concrete dust from the road in agitation. Shards of needle-like teeth snapped eagerly, its black forked tongue tasting the scent of her fear in the air. Its jaw released like a trap door, gaping wide, the ropy tendons bunching and lengthening.

Fear locked Julia’s joints, as long, clawed digits stretched and rotated at an impossible angle to close around her wrist. The steel grip crushed the knife from her hand, sending it clattering between her feet. Responding to the nearness of an easy kill, a second set of lower forearms unfurled like lethal anemones from the protective curl of its abdomen.

The Chittrix’s grip tightened and the fine bones of her hand grated against each other as it, hooked her flat against its glossy exoskeleton. Julia struggled, her nostrils seared with the acrid scent of soil and blood. Crushing panic surged through her body, and she bucked hard, twisting to free herself from the obsidian nightmare. She kicked but the thick haunches were spread too far for her boots to connect, and its grip tightened as she thrashed. Its head twisted, preparing to unleash lethal damage and then—

A blaring cacophony.

High-pitched alarm notes pierced her skull and sleep-muddled brain. She jerked, causing her cheap metal chair to topple, pain exploding through her temple as she collided with the floor. Air wheezed from her stunned lungs as she lay crumpled, hands stinging from hitting the table leg on the way down.

She gasped as terror flooded her body. Rolling onto her side, she freed herself from the fallen chair, her hands and feet still uncoordinated as she scrambled to the wall, seeking protection. In front of her, a laptop sat on the table, digits scrolling furiously across the flashing red screen.

Blood pounded in her ears as she tried to slow her breathing, her head whipping around the room, searching for the Chittrix of her dreams. She clutched a micro-soldering iron in her fist, brandishing it in front of her like a weapon.

I’m alone.

Her head dropped in exhaustion.

Just another nightmare.

Her sleep hadn’t been peaceful for many years, but now the night terrors of old shared the space in her head with the Chittrix. She rubbed her sore, gritty eyes. She couldn’t remember when she’d last slept in peace or for more than a few hours at a time. Her body sagged, and she rested her head on the cold floor, gathering herself. She waited for the world to disappear and leave her alone, but the whooping wail of the alarm continued.

The laptop.

Fuck.

Julia raised her head.

Her laptop. She’d been running calculations when she’d dozed off, tipped over the edge by sheer exhaustion.

She straightened, sliding her back up the wall on adrenalin wobbly legs. Taking a breath, she threw her soldering tool on the table and bent over the machine. A warning dialogue box berated her.

The power supply to her laptop and the other five computers it controlled was failing.

Her fingers flew through operating system codes, trying to isolate the source of the problem. Energy supply was erratic in the dilapidated Command Base bunker, but usually only in the middle of the day when requirements were high. Julia glanced at her watch. Two o'clock in the morning. What was going on?

She’d been running acoustic equations for the Sweeper, the explosive device she’d created in the fight against the Chittrix invaders. Oblivious to the importance of her work, the mainframe was showing no mercy, shutting the computers down one after another as the power reduced.

Three were down already, and the remaining two were halfway there. If she didn’t work quickly, she was going to lose everything—all the research she had amassed since the Chittrix had attacked Earth.

Twelve months ago, the Chittrix had blasted through Earth’s atmosphere in a global meteor shower. Julia had been presenting at a weapons development conference in Paris that night and had watched the streaking fireworks as they fell to earth with hidden burgeoning alien life on board. The world’s top scientists had approached the meteors with curiosity—before the rocks had cracked open, disgorging alien Chittrix in devastating waves of insectoid life. Under military escort, she’d travelled back to her Ministry of Defense weapons-research lab near London, arriving only a day before the entire infrastructure of humanity had collapsed under the weight of the Chittrix onslaught.

Julia squinted at the screen but it remained blurry. She touched the bridge of her nose. Damn glasses were missing. She scanned the floor and huffed as she scooped them up and slid them back on.

Frustration sang in her veins as she tried to isolate the source of the problem. The dead faces of her family, friends and work colleagues were still bright in her mind’s eye. She was not going to lose this work.

She switched tactics, deciding to play it safe and back everything up. Julia was close to making the Sweeper more compact and there was two days worth of unsaved calculations on the damn computers. She huddled over the monitor, siphoning off her research as quickly as possible from the main terminal to the storage systems within the aging base while the ancient hardware pondered her transfer requests. Coloring the air blue with expletives, she ran her palm across her face. It was sticky and smelled of burnt solder.

“C’mon. C’mon.” She bounced on the balls of her feet. Nothing in this place worked the way she needed it to, and it was driving her mad.

The fluorescent strip light above her head dimmed for a few minutes before surging back on. Julia straightened. The main power supply too? She glanced down, watching the red bar progress to green.

Finally.

The progress bar flashed green and complete. Her data was filed safely, accompanied by the acid tang of hot dust and plastic.

She took a breath, struggling to regain her focus. She was so tired. She’d slept badly again last night, plagued by relentless dark dreams that left her exhausted when she woke.

Doesn’t matter. The Chittrix will pay.

Her Sweeper was an acoustic weapon. It pulsed hypersonic sound that matched resonance within the alien insectoid bodies before detonating them at a molecular level. It came too late in the first battle for Earth, a bitter pill that Julia swallowed on a daily basis. She couldn’t bring back the dead but she could make damn sure the remaining survivors had a weapon to go forward with.

Since then she had worked relentlessly to refine the Sweeper, reducing it from a bulky cube with coded keys to a handheld weapon that could be used by anyone. Success was imminent now. She was sure of it, and she wasn’t going to be derailed this close. She had fought so hard to get to this point, scavenging remnants from the destroyed capital and painstakingly piecing her engineered baby together.

The light above her head flickered once more and then died.

Darkness encompassed her, broken only by the light from the computer monitor. She hurled a pen at the wall and screamed a volley of expletives into the suffocating darkness.

She pressed two fingers to her temples. Think Julia. The system is overheating. Power’s failing.

Shit.

The hydroelectric plant.

In the basement.

She stifled a shiver. I can do this.

By the time the emergency lighting clicked on in a pallid wash of blue light, she had already yanked a pulse rifle down from its berth above her, her thumb activating the charge. It glowed green, fully enabled. At least something was bloody working. Julia lifted her chin. In this new world, she no longer had the luxury of avoiding difficult situations.

She looped the strap around her neck, adjusted the weapon and triple-checked the safety. Flashlight. She grabbed one from the desk drawer at the last second. If she'd learned anything in the last year, it was that it didn’t hurt to be prepared.

* * *

Julia picked her way down the hall, guided by the erratic flashlight beam. Tight control of energy consumption meant the corridor was dark and silent at night and the small population of seventy or so survivors, an eclectic mix of military and civilians, were mostly asleep.

Three months ago, Julia had arrived at the decommissioned underground bunker known as the Command Base with Anna Ward, her colleague and friend. They had escaped from their weapons lab at Magdon Down on the outskirts of London when the lab was attacked and razed to the ground by the alien Chittrix. With the help of survivors from the CB Julia and Anna had escaped to relative safety and since then the aging CB buried deep in the Wiltshire countryside had been home.

Julia sped down the stairs to the basement. Extending a hand in the wavering darkness, she yanked open the door and stepped into the cavernous room. Here the light was slightly brighter as a lazy loop of blue illumination from alarms set high on the wall pulsed across her. Footsteps sounded behind her, and as she spun, two men followed her into the basement.

Both were tall, but Garrick was the broader of the two. He carried a flashlight and kit bag in one hand, while his other gripped the machete he usually wore low on his hip. His hand tightened on the handle of the weapon, toned muscles flexing along his forearm. As he stepped forward, Julia was reminded again why Anna had fallen so hard for this ex-special forces rogue. Garrick squinted against Julia’s light, his palm raised. His handsome face shifted into a smile of recognition.

“Julia? What the hell are you doing down here?”

As he spoke, the second man stepped out of the shadows. Her heart leaped.

Sawyer.

Her gaze danced over his tall, rangy body. He still made the breath catch in her throat with the hot male virility he exuded from every damn pore. Leaner than Garrick, Ben Sawyer hit all the right buttons for Julia and had been doing so repeatedly for the last three months, ever since he had brought her from Magdon Down to safety.

Her mouth went dry as he approached with easy, loose-limbed strides. The shaved sides of his skull gleamed under the alarm pulses, the top of his head dusted with a short mohican that she loved to run her hands through. Sawyer acknowledged her with a tiny, secret smile, and her heart jumped into her throat. Deep dimples, too charming for a Metropolitan Police Officer, dented his cheeks and only added to the effect.

"Working late, Dr. Simmons?" Sawyer maintained a professional distance, skirting her body as if they were only acquaintances. Nothing was further from the truth.

“Uh huh. Power failed in the middle of my simulation.” She kept her tone neutral. Businesslike.

The alarm light continued to rotate above their heads in slow blue sweeps.

“Where the hell can I turn the lights back on?” Garrick asked as he stalked to the back of the vast room, his flashlight jerking and bobbing.

Sawyer brushed past her, and her skin exploded in tingling prickles. His arm deliberately bumped the curve of her breasts, firing spirals of sensation down her spine. Up close, he towered above her, his hazel eyes slowly appreciating every inch. She tore her gaze away. When he sized her up like that, she found it difficult to concentrate.

He squeezed her arm with a soft stroke from shoulder to elbow before heading toward the back of the vaulted room. She cast her eyes over his retreating back, distracted by his lean hips and trousers that hugged...everything. She swallowed, shaking her head at her own fallibility. Now was not the time to be thinking about Sawyer naked in her bed.

She turned and followed him down the towering banks of electrical plant, her flashlight beam dancing over the large coolant system. It didn't make any sense that everything had failed based on an electrical fault. She ran her fingers over the machinery and pipes. They were warm, warmer than she would have expected.

She kept walking toward the back of the room, tracking Sawyer’s broad shoulders. Fifty feet in, the pipes and endless rectangles of metal equipment came to an abrupt halt beside a high railing. Julia tipped her flashlight downwards over the barrier into black nothingness.

Silvered whispers of water thirty feet below curled into her ear, sending tiny shivers of apprehension dancing across her skin. Being this close to the water gave her cold sweats.

Sawyer came up beside her, bumping closer than was necessary. He scanned the ceilings and walls around them, his light struggling to penetrate the uppermost arcs of the vaulted ceiling. Chittrix could climb walls and suspend from ceilings, as well as fly. But the beam only skimmed over grey, nondescript space. He leaned over the edge of the rail and whistled.

"What the hell is down there?" he asked.

Cool damp air rising from below smothered Julia’s face in a suffocating web of moisture. Her throat constricted, and her heart raced a little harder. "Water that supplies both our power and coolant systems. We're sitting on an ancient underground river that runs from London out to the sea."

Sawyer gave a low grunt and sidestepped along the rail.

Julia took a deep breath and clutched cold metal, waiting for her pulse to decelerate. Her heart was pounding against her ribs with such ferocity, she was sure Sawyer must be able to hear.

Twisting emerald weeds flashed through her mind. They danced and swayed in the dark water, a living curtain revealing teasing glimpses of a small, pale hand before weaving together once more. Streams of silver bubbles lazily ascended as her father kicked toward the thick tangle of weeds, deep at the bottom of the lake.

“Julia?”

She started as Sawyer’s voice dragged her back to reality.

“What?”

"You okay?” he asked, his voice gentle.

“Yes. No. I…just freaked out.”

He pressed a strong hand to the small of her back. Warmth and reassurance soaked through her, and her muscles relaxed under his caress.

Garrick approached them, a pulse rifle now in his hands as he scanned the walls. Sawyer’s hand slipped from her body, but she could still feel the imprint of his palm.

Garrick frowned. “Okay, nothing’s happening with the lights. Something’s stopping the generator from powering back up. Julia. You got anything?”

She rubbed her temple. “There’s no power to run diagnostics. We’ll have to check the coolant system for a blockage.”

Sawyer wrinkled his nose and peered into the abyss. A ladder was bolted to the wall at his feet, descending into nothingness. “Is the coolant system going to be where I think it is?”