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Red light enveloped the giant rat's corpse, including the severed limb, and then it all fused into the Crimson Book's mark on Lisa's hand.
When the light faded, Lisa opened her eyes. "The contract worked," she said. "It's a Mutant Rat."
With a thought, the creature reappeared before them. It was half a meter long without the tail; with the tail, nearly a meter—comparable to a medium-sized dog. Its patchy fur and exposed bone gave it a rotting appearance, but its movements were quick, predatory.
"I feel stronger, but not by much," Lisa continued. "But this Mutant Rat has a skill…"
She glanced at Jin, wondering what skills he possessed. His had to be more formidable.
Jin noticed her look. "What skill?"
Lisa didn't hesitate. Sharing information built trust. "Rat Poison (Weak). Its claw strikes and bites carry a poison that can cause infection if untreated."
Mark muttered, "Like a komodo dragon, huh?"
Jin nodded. "Let your Mutant Rat scout ahead. My Summon will follow second. Mark, yours takes the rear."
"Got it," Mark said.
Their teamwork was solid now. The brief exploration had proven they could rely on one another.
On the sixth floor, three apartment doors stood wide open. Bloodstains and impact marks covered the frames—clear signs of Zombie activity.
Lisa sent the Mutant Rat toward the nearest open door. It skittered low, avoiding the corpses in the hallway, and stopped at the threshold. The door's lock was broken, the wood gouged with claw marks.
Mark whispered, "Must have been the two we killed earlier."
A Zombie's strength surpassed a normal human's—twisted bodies and rage gave them power. A security door wouldn't hold against sustained assault.
Inside, the living room was destroyed. The sofa was soaked in blood, and a body lay on it, partially consumed.
"Look for anything useful. Food, medicine, tools," Jin said.
They entered. The Summons cleared each room first, ensuring no Zombies lurked in closets or behind furniture. Jin searched the kitchen and living room. Mark took the secondary bedrooms. Lisa went to the master bedroom.
The kitchen was relatively tidy. The refrigerator and cabinets were intact, but when Jin opened the fridge, a wave of rot hit him. Without power for over a day, everything inside had spoiled. He closed it quickly. Rice and sealed seasonings might still be usable, but anything perishable was a risk. Even defrosted meat could cause illness—and without doctors, diarrhea could be a death sentence.
"Jin."
Mark's voice was low, tense. Jin moved to the secondary bedroom.
Mark stood at the door, expression grim. "There's a survivor. But she's in bad shape."
He pointed to a large floor-to-ceiling wardrobe. The doors were open. Inside, a young woman huddled among clothes, her face pale, eyes shut, body trembling. A steady drip-drip of blood fell from her abdomen.
"Get her out. Lay her on the bed," Jin said.
His Summon lifted her carefully and placed her on the mattress. Lisa came in, summoned by Mark.
She examined the woman, then straightened, shaking her head. "There's a bite wound on her abdomen. She's feverish—infection is setting in. She's lost a lot of blood."
Blood still seeped from the wound. Lisa pressed a cloth against it, but the bleeding was slow to stop. The woman's skin burned with fever.
Silence hung between them. Jin finally spoke. "Give her water. See if there are any anti-inflammatories. If she doesn't improve by tomorrow…" He left the sentence unfinished.
None of them were doctors. Under these conditions, survival was a matter of luck.
Lisa nodded. "I found some medicine in the master bedroom."
They treated the woman as best they could, then closed the bedroom door and gathered in the living room.
Lisa laid out what she'd found. "Snacks, household meds, two power banks. Enough charge to keep flashlights running."
Mark added, "Not much in the other rooms. Just a fruit knife." He looked at Jin. "Do we need to strip metal this time?"
He remembered Jin needed metal for his Summon's fusion. The stronger Jin became, the safer they all were.
Jin considered. Fusing Common Metal to LV2 had taken several hundred pounds. LV3 would require far more—likely an entire building's worth of scrap, unless they started tearing out load-bearing walls. No one in their right mind would do that.
"Not now," he said. "We keep scavenging and clear the lower floors. Without refrigeration, fresh food is gone. Canned goods, preserved meat, rice, pasta, snacks—that's all we have left. Eventually we'll have to go outside. The sooner we clear the floors below, the sooner we can plan."
He hadn't found much food in the kitchen either—just a small bag of rice and flour. Their supplies were dwindling.
"Alright," Mark said. "Let's keep going."
They worked through the sixth floor apartment by apartment. In one unit with a busted door, they found another Zombie. Lisa's Mutant Rat struck first, leaping for the throat and tearing out a chunk of flesh. Jin's Summon followed, its Claw piercing the creature's chest.
The Rat's poison wasn't strong, but against a human—or a Zombie—it would be devastating.
By late morning, they had cleared the entire sixth floor. Apart from the unconscious woman, there were no other survivors. One apartment was empty; the others showed signs of slaughter.
The scavenged supplies were meager: three pounds of preserved meat, thirty pounds of rice and flour, five bags of dried noodles, ten packs of instant noodles, and a collection of snacks. Medications were mostly common drugs, nothing special. The haul barely filled three backpacks.
They decided to push down to the fifth floor.
The situation there was similar. In the hallway, three Zombies gathered at the far end, clustered in front of a closed door. They spotted the group and charged.
Mark and Lisa moved in tandem now. Mark's Summon grappled one Zombie, holding it steady while Lisa's Mutant Rat leaped onto its head, gnashing until the skull gave way. The two worked seamlessly, dropping the first creature in seconds.
The remaining two rushed forward. Jin's Summon met them head-on. A heavy punch sent one crashing into the wall; a swipe of its Claw severed the creature's neck. The other shrieked and lunged, but its claws scraped uselessly against the Summon's Metal Body. A moment later, the Summon's Claw drove through its heart.
The hallway was slick with blood, but the three had grown accustomed to the sight.
"Let's start with this room—" Jin began.
Creak.
The door in front of them swung open. A thin man with glasses peered out, his face pale, expression wary. He looked at the corpses, then at Jin, Mark, and Lisa. His voice cracked when he spoke.
"You… you're from the rescue, right?"