The air inside the breach of Sierra One was heavy, laden with the metallic tang of dried blood and a cloying, chemical scent that made Ethan's nose wrinkle. The overgrown path led into a series of smaller, abandoned research outbuildings, their windows dark, their doors hanging ajar. Anya, Jax, and Ethan moved in a tight, silent formation, their footsteps muffled by the thick undergrowth.
**\[Objective: Infiltrate Sierra One Outpost. Status: In Progress. Experience Gained: 50/100 (halfway to completion).]**
Ethan's senses were on high alert. His **Intelligence* stat, now at 11, seemed to sharpen his perception, allowing him to pick up subtle details: a broken twig, a scuff mark on the dirt, a faint, rhythmic scratching sound from one of the darkened buildings. His *Ranged Accuracy* skill gave him confidence in his pistol, though he preferred the silence of his hatchet for now.
As they crept past the first outbuilding, a sudden, blurred movement caught Ethan's eye. A "Runner." It burst from the shadows of the building's entrance, a gaunt, terrifying blur of speed, its limbs elongated, its joints popping audibly as it launched itself at Anya.
"Runner!" Ethan hissed, a split second before Anya spun, her rifle snapping up.
The Runner was incredibly fast, closing the distance in a blink. Anya fired a burst, but the creature's erratic, almost spastic movements made it a difficult target. One shot grazed its shoulder, another hit its leg, but it barely seemed to slow.
Ethan reacted instinctively. With a burst of his *Agility*, he intercepted the Runner, hatchet raised. His **Melee Proficiency** guided his swing, a clean, powerful arc aimed at its head. The hatchet bit deep, the Runner's momentum carrying it past him before it crumpled to the ground, twitching. It was unnervingly resilient even after a headshot.
*\[High-threat Mutation (Runner) eliminated! Experience Gained: 50 EXP.]*
*\[Current Experience: 100/400.]*
"Good kill, Ethan!" Jax whispered, his crossbow now aimed at the fallen creature.
Anya quickly reloaded her rifle, her eyes scanning the area. "They're faster than anything I've seen. And that one took multiple hits before you dropped it."
"Still active," Ethan pointed with his hatchet to the twitching body. "Needs more." He brought the hatchet down again, definitively.
They continued their silent advance. The encounter had raised the stakes. These weren't just numerous; they were dangerous. They needed to find a way to distinguish active from neutralized targets.
As they approached a larger, main research building, a low, guttural chittering sound emanated from above. "Lurker," Jax mouthed, pointing to the roofline.
Ethan peered up. A "Lurker" was pressed flat against the rough concrete wall, blending almost perfectly with the shadows. Its body seemed to contort, mimicking the texture of the building. It was utterly still, waiting.
*\[Threat Detected: Lurker (Stealth/Ambush). Recommendation: Engage from range or preemptive strike.]*
"It's an ambush predator," Ethan whispered. "It's waiting for us to get close."
Anya aimed her rifle. "On three. One… two…"
Before she could say three, the Lurker launched itself, not at them, but towards a narrow gap in the building's exterior, a maintenance hatch. It was trying to escape, or reposition.
"It knows we're here!" Jax shouted, firing his crossbow. The bolt struck the Lurker's shoulder, pinning it momentarily.
Anya opened fire, her rifle spitting rounds. Ethan drew his pistol, his **Ranged Accuracy** skill kicking in. He aimed for the head, squeezing the trigger. The pistol barked, and the bullet struck the Lurker's skull with a sickening impact. It convulsed, tearing free of the crossbow bolt, and scuttled away into the darkness of the maintenance hatch, a high-pitched shriek echoing behind it.
"Damn it!" Anya cursed, lowering her rifle. "It got away."
"It's hurt," Ethan said, holstering his pistol. "But it knew we're here. This place isn't just overrun. It's actively defended by these things. They're intelligent."
*\[High-threat Mutation (Lurker) damaged. Status: Fled. Experience Gained: 25 EXP.]*
*\[Current Experience: 125/400.]*
They had infiltrated Sierra One, but the cost was clear: they were dealing with a new, terrifying breed of infected, ones that strategized and fought back. This was no longer just a hunt; it was a desperate expedition into the heart of a rapidly evolving nightmare.