The warning from the System was not a suggestion; it was a final, stark notification of existential threat: Tier 4 Bio-Subject (Evolved/Unstable). The sheer energy density displayed on the scanner eclipsed even the signature of the defunct Glacier Leviathan. Lin Fan knew he had to abandon the small containment room immediately. He couldn't risk fighting a Tier 4 creature amidst fragile chemical vats.
Tactical Withdrawal and Ambush Setup
Lin Fan executed a flawless tactical retreat, utilizing the complex's layout as a tool. He didn't run towards the exit; instead, he led the converging subject into a large, rarely used Biological Testing Bay on Sub-Level 2—a vast, open, high-ceilinged room designed for handling massive, unstable specimens. This was his arena.
He used the transit time to prepare. He activated his Cryogenic Manipulation, channeling concentrated energy into the tiled floor. He wasn't aiming for a simple freeze; he created a sprawling, near-invisible layer of Hyper-Crystalline Ice, turning the wide floor into a treacherous, frictionless sheet of glass, perfect for disrupting heavy momentum.
Next, using 40 of his remaining SP, he fabricated two small, potent Tier 2 Concussive Charges. He strategically placed one near the primary ventilation hub and the second near a major, exposed LOX (Liquid Oxygen) pipe—a relic of the facility's cryogenic storage experiments. These were not meant for damage, but for catastrophic environmental disruption.
Finally, he used the A.R.R.M.'s capability to rapidly synthesize a small vial of volatile, high-smell Chemical Disorientation Agent. He positioned himself behind a heavily reinforced titanium observation booth—the only structure likely to withstand a direct hit—and released the non-lethal, high-irritant agent near the entrance.
The Apex Strain Revealed
The junction doors leading to the testing bay didn't open; they were violently shredded.
The Tier 4 Bio-Subject emerged, and Lin Fan instantly realized why it was designated 'Apex.' It was a colossal, hulking figure, roughly three meters tall, its body a dense mass of black, hyper-developed muscle. Unlike the crystalline mutants, the Apex Strain radiated a fearsome, tangible internal heat. Steam rolled off its massive, armored shoulders, instantly vaporizing the residual ice on the entranceway.
The creature's sensory clusters—multiple glowing red eyes—immediately locked onto Lin Fan's thermal signature behind the booth. It inhaled, then released a guttural, earth-shaking roar that was instantly cut short as the chemical disorientation agent hit its evolved sensory organs.
The Apex Strain paused, shaking its massive head, momentarily stunned.
It then launched itself forward, attempting to cross the vast bay in a single, kinetic leap.
The trap sprung.
The creature's intense heat instantly melted the surface of the Hyper-Crystalline Ice, but the sheer momentum and mass, combined with the underlying frictionless structure, betrayed it. The Apex Strain slid uncontrollably, smashing into the side wall of the testing bay with a force that cracked the reinforced concrete.
Its primary weapon was instantly unleashed: a devastating plume of superheated, corrosive acid vapor, aimed directly at the observation booth. The vapor was designed to melt containment and neutralize biological threats.
Ssssssssss! The vapor hit the titanium. The metal surface immediately began to bubble and slag under the intense heat and chemical activity.
Lin Fan had calculated this. He channeled his Cryogenic Manipulation with every ounce of his will, not at the creature, but at the thermal trajectory of the vapor plume, creating a localized pocket of super-cooled air. The attack was violently destabilized, scattering into inert, corrosive dust that showered the booth but failed to penetrate the integrity of his A.E.S.M.-enhanced armor plating.
The Calculated Kill
Lin Fan knew the creature's massive internal heat generation made a prolonged fight in the cold futile. He had to hit the core vulnerability: internal stability.
The moment the Apex Strain recovered from its slide, Lin Fan remotely detonated the concussive charge near the central ventilation hub. The blast was minor, but it created immense localized pressure and vibration near the ceiling.
As the creature looked up, momentarily distracted, Lin Fan targeted the LOX pipe with the second charge.
BOOM!
The LOX pipe ruptured, releasing a catastrophic torrent of liquid oxygen. The ambient temperature in the testing bay dropped by over 100 degrees in a single second. The extreme, sudden thermal gradient caused the Apex Strain's external heat regulation system to seize violently.
The creature roared in agony as a thick layer of brittle, crystalline frost instantly coated its superheated muscle tissue. Its movement faltered; the energy fueling its Instantaneous Regeneration was momentarily overwhelmed by the external shock.
This was the window.
Lin Fan sprinted from cover, ignoring the freezing pain, and drew the Apex Strain's attention. The creature lumbered toward him, driven by pure instinct, but its regeneration was slow, the frost stubbornly clinging to its joints.
Lin Fan focused his AR-15. He did not aim for the head or the chest. He targeted the exposed Tier 4 Bio-Core—a massive, dark purple organ pulsing faintly beneath a vulnerable patch of muscle tissue near the shoulder blade.
He unleashed a sustained burst of Cryo-Rounds.
BRRRRRRT!
Each Cryo-Round delivered kinetic force followed by a localized thermal shock. The barrage punched through the weakened muscle and slammed into the core.
The Apex Strain emitted a final, high-pitched, agonizing shriek that ruptured the room's internal systems. The core pulsed violently, then exploded internally in a flash of purple energy. The formidable body collapsed into a puddle of inert, smoking biological sludge, its internal heat extinguished.
Final Acquisition and Departure
Lin Fan stood over the residue, his armor steaming as it equilibrated the temperature. He was exhausted, but the sensation of having defeated a Tier 4 threat through calculation, not brute force, was intoxicating.
The System confirmation was immediate:
[Threat Neutralized. Tier 4 Apex Strain Defeated.][Tier 4 Bio-Core (Apex Strain) Detected. Energy Density: Catastrophic.]
He cut the massive, still-pulsating Tier 4 Bio-Core from the sludge. It was the color of deep purple, radiating pure, raw organic energy.
[Tier 4 Bio-Core Acquired.]
Lin Fan initiated a rapid final sweep. He secured the remaining high-value research notes—the chemical formulas and evolutionary data compiled by the facility—and ensured no critical data was left for future competitors.
He raced back to the waiting Cryo-Skimmer, which had remained securely on overwatch. He strapped the Core into a shielded compartment and engaged the launch sequence.
The Cryo-Skimmer rose silently into the frozen sky, leaving the ruined BRF-7 complex behind. Lin Fan, carrying the combined wealth of the BRF-7—the Tier 3 Reagents, the evolutionary data, and the ultimate Tier 4 Bio-Core—had secured the final keys to his own evolution.
He set the autopilot for home, his gaze fixed on the coordinates of his fortress. It was time to synthesize the Tier 4 Evolution Serum. The time for simple survival was long past; the era of true ascension was about to begin.
(Author's Note: The Tier 4 Apex Strain is defeated, and the ultimate Bio-Core is secured! Lin Fan now possesses the final ingredients needed to synthesize the Tier 4 Evolution Serum. The next chapter will focus on this monumental breakthrough and the shattering new power it unlocks. Are you ready for Tier 4? Drop a Power Stone if you're excited for Lin Fan's final evolution!)