The door swung open, sunlight blazed, blinding the camera. The view switched to the outside, looking down upon a grassy meadow, a line of oaks in the distant background. Kat was shoved outside, stumbling into view, shading her eyes with her small shield against the summer glare.

“TURN YOURSELF IN NOW, OR HER FATE WILL WORSEN OVER TIME. THIS IS YOUR ONLY WARNING.”

Lisa needed no time to decide.

WWKD?

She knew what Kat would want her to do.

She hurried down the hall—not to turn herself in but to make her escape while most eyes here were fixed on those screens, prepared to enjoy whatever blood sport was about to ensue. And Lisa knew from the shield and the club that some gladiatorial battle was about to start.

She caught fractured glimpses as she ran with the child, gone quiet again for now, likely jostled back to sleep by her running. In stuttered snatches, she saw Kat head out into that field, wading through the grasses.

Be careful, she wished her friend.

2:18 P.M.

Kat stalked across the thigh-high grass. She carried a hard steel shield, two feet square, strapped to her forearm. In her other hand, she wielded a three-foot length of hollow pipe. She breathed deeply, readying her body, flushing oxygen into her muscles. Her senses stretched out.

The tall grass was mostly green, redolent of summer, the scent growing stronger as she crushed through blades with her slippers. The edges of her gown snagged on bristled weeds. Her ears caught the twitter of birdsong, registering it but filtering it into the background, along with the distant sound of tumbling water to the northwest and the sweep of gentle wind through leaves.

She knew the hunters would be coming.

She’d overheard the two scientists talking—Fielding and Blake—preparing her, deciding which weapons to test.

The battlefield is the ultimate crucible of Darwinian natural selection, Fielding had explained to the other researcher. Survival is the main drive of evolution. And it’s no different for our pods. For our weapons to learn, they must be field-tested, battle-hardened. With each new challenge, new synapses of the cybernetic brains will grow and expand. But we must test the pods with ever-harder challenges.

She had seen those hexapods, as she heard them called: crab-like titanium killing machines, equipped with razor-sharp legs, slashing daggers, and drilling burrs. Other variants lined the workbench. The worst looked like a large, bloated tick, its legs as skinny as ice picks.

Beyond the workbench, deeper in the lab, larger creatures, the size of small black bears, had lurked, in various stages of assembly.

Kat strode across the meadow, hefting the shield to test its weight and swinging the pipe to judge its balance.

We’ve pitted the hexapods against unarmed opponents in the past, Fielding had finished. Today we’ll test them against the next level of weaponry: blunt weapons and shields. We will send wave after wave, escalating the numbers each time, until they learn, adapt, and defeat their opponent.

A rustle to her left alerted her. She swung around, dropping her shield low. The grasses stirred as something raced low through them, cutting across the meadow like the fin of a shark through water. She saw four other trails swinging wider, intending to outflank and circle her.

Clearly, they were capable of coordination.

Good to know.

Fast as greyhounds, the hexapods churned through the fields. She’d never make the tree line, so she didn’t bother trying. She would make her stand here, using this first wave—if she survived it—to learn and adapt.

Nothing said she couldn’t evolve as readily as her opponents.

First, she didn’t want to be in deep grass. She wanted a better field of view. With seconds to spare, she used her shield as a press and stamped a swath of grass around her, pushing the stalks outward, creating a thicker natural palisade. She left one section open, a gate into her little nest.

The first hexapod hit that palisade broadside, got wedged in the wall of compacted grasses. She identified the gleam of its titanium carapace and speared her pipe down at it, using all of her weight. Metal crunched under the battering ram. It didn’t kill the beast, but it incapacitated its sensory system, sending the pod zipping away in a spiraling blind curve.

The other four, perhaps wirelessly sharing the experience of the first, veered away from a direct attack. They swarmed in a circle. Then one cut away, shooting toward the opening, sensing the chink in her shield—not knowing it was a trap.

It cut into her nest, but she was ready. She used her pipe like a golf club and batted it square in the front sensors, crushing the electronics and sending it flying. It landed on its back and didn’t move.

A weak spot.

The other three circled, clearly plotting something, then, once decided, the trio arrowed toward the opening together, plainly trying to overwhelm her.

Sorry, we’re closed for the day.

She slammed her shield’s edge into the soft loam, sealing the opening to her nest. The lead pod hit the shield with a loud clank. She stabbed downward, again and again, like a piston. She shattered most of its legs, leaving it crippled.

The other two veered away, plotting their next move.

Kat wasn’t waiting. She found a fist-size rock and underhanded it into the grasses. The movement drew one of the creatures. It shot in that direction, but it was only fooled for a few seconds. Once the rock stopped moving, it stopped hunting.

It knew the rock wasn’t alive.

The test confirmed the hexapods had motion sensors, but they must be backed by infrared, reading body heat, a mark of living creatures. Since the pod chased the rock, she doubted its visual acuity was very sharp. They could be fooled.

What about sound and smell?

The two pods didn’t give her another chance to find out. They zoomed in from opposite directions. One headed toward the shield; the other, the natural grassy palisade.

Kat snatched her shield back up, opening her nest again, allowing the first one to shoot inside. The second got delayed trying to push itself through the grass, employing some buzzing blade to chop into her space.

The first spun on a dime and came at her. She shoulder-dropped, putting all her weight on the edge of her shield, turning it into a guillotine. She crushed the front end, driving it into the soft soil.

The second burst through the palisade, leading its charge with a spinning horizontal saw blade.

She leaped to the side as the second rammed the first, finishing the job for her with its diamond blade ripping open the underside of the other pod. The first retaliated in a defensive death reflex. Razor-sharp legs drilled into crevices, peeled open the carapace, and ripped out the glass-enclosed brain.

In seconds, they’d killed each other.

Kat crouched, examining their weaponry, peeking at the arsenal under their carapaces. She noted a small, dart-like apparatus, the side marked with the designation M99.

Etorphine hydrochloride.

A powerful game-animal tranquilizer.

Strong enough that one drop could immobilize a man.

Knowing her opponents better, she stood and stared over at the small bunker through which she’d exited the facility. She knew they were watching. She just glared.

Let’s see what else you’ve got.

She turned and sprinted for the tree line.

2:28 P.M.

“She’ll do well,” Emmet Fielding said, forming a temple of his fingers before his lips, studying the bank of monitors. “Very fit.”

Edward sat beside him at the curved bank of computer screens. He gently fingered his broken nose, taped up after Lisa’s surprise attack. He watched the woman flee out of the view of one camera and into another. She fled through a dark forest of oaks, pine, and spruce.

“Aren’t you upset that she dispatched your weapons so quickly?” Edward asked.

A flap of fingers waved away his concern. “You can’t make an omelet without breaking a few eggs. Porsche destroys fleets of their sports cars in their testing lab and field trials. That’s how you build the best. And I won’t settle for anything less.”

Edward had noted how the man’s pulse beat faster in his throat during the attack. He suspected this testing was as much a blood sport to him as it was science. But that wasn’t his concern.

After seeing that, surely Lisa would return with the boy.

“Any word?” Edward asked.

Fielding made a noncommittal noise, plainly not interested. Whether Lisa showed up or not, he intended to continue this test until the woman on the screen was a macerated ruin.

He glanced to the clock. Petra had also gone off on her own to search for Lisa. After being caught off guard and struck in the head, his research associate was out for blood, hunting as diligently and as coldly as those steel creatures.

Fielding sat back from his workstation, stretching. “I think we’re ready for round two.”

“How many will you send this time?”

“A full score, I believe. Twenty. But she’s shown so much promise—truly remarkable—I think we’ll skip straight to the next level of challenge. Introducing a new element.”

Fielding glanced behind him to the back of his lab. Larger pods hulked back there, on four limbs, each leg ending in curved claws patterned after a sloth’s, perfect for gutting prey. Edward had seen how fast the quadrupods could move, bone-chillingly frightening to witness.

“I think I’ll send up two,” Fielding said and tapped buttons with a bit of bravado.

Blake stared at the running woman.

She had better hope Lisa changed her mind and returned with the child—though, in the end, it would not make any difference.

Not for either of the women.

2:29 P.M.

Lisa fled down a long, dim corridor, the baby under one arm, the knife ready in the other. She had watched in fleeting glimpses Kat’s successful battle with the metal creatures—but more to come had been promised, and she had no doubt it would be delivered.

She glanced above her head.

I should be under the red zone by now.

By her best estimate from the live feed, she was, unfortunately, fleeing in the opposite direction from Kat. She could not offer her friend any help—other than to survive herself.

She continued down the corridor that transected the huge complex, passing through a zone designated as black. This area appeared empty but not deserted. The air had a feeling of expectation to it, like before a lightning storm. The source appeared a few yards ahead. To the right opened a vast, cathedral-size warehouse. A full flight of steps led down to the lower floor.