The center of the safe zone hummed with faint violet light.
A tall stone monolith had materialized out of the dirt, its surface covered in softly glowing runes. Dozens of survivors were crowded around it, shouting at the air or tapping invisible floating screens with dirt-caked fingers.
Leo walked over, keeping his hands tucked inside his hoodie pockets. He held his three precious Fragmented Beast Cores tightly in his right palm.
System Shop, he thought.
A crisp interface snapped into view before him. Unlike his personal status screen, this one looked like a digital storefront divided into neat categories: Weapons, Armor, Consumables, and Miscellaneous Raw Materials.
He navigated straight to the sell tab.
Fragmented Beast Core Common. System Purchase Value: 5 Credits each.
Leo transferred two of his cores into the interface.
Two Fragmented Beast Cores sold.
Gained 10 System Credits.
Current Credit Balance: 10 Credits.
Leo checked his remaining core. It was his seed inventory—the single unit he needed to keep for manual replication.
Now came the real test: searching the shop for arbitrage opportunities.
He opened the Consumables tab first. Basic healing salves cost 15 credits. Low-grade mana potions cost 25 credits. Bread cost 1 credit per loaf.
Then he opened the Weapons and Tools tab.
Basic Iron Dagger. Common. Price: 20 Credits.
Damage: Plus 3 Physical. Weight: 0.4kg.
Basic Wooden Shield. Common. Price: 15 Credits.
Durability: 50 out of 50. Weight: 0.9kg.
Leo scrolled past the weapons and clicked on Raw Materials.
Low-Grade Energy Crystal. Common. Price: 50 Credits.
Effect: Restores 50 Mana upon absorption OR sold for 50 System Credits. Weight: 0.1kg.
Leo's eyes narrowed.
There it was.
A Low-Grade Energy Crystal cost 50 Credits and restored 50 Mana.
His maximum Mana capacity was 50.
His manual replication skill cost 49 Mana.
If he could buy just ONE Low-Grade Energy Crystal for 50 credits, he could duplicate it.
One crystal would give him 50 Mana when absorbed. He could spend 49 Mana to duplicate a second crystal, leaving him with 1 Mana remaining and a fresh crystal. Then he could absorb the new crystal, instantly refill to 50 Mana, and duplicate another.
It was a closed loop. An infinite loop.
"I need 40 more credits," Leo murmured under his breath.
He currently had 10 credits and 1 Fragmented Beast Core. To reach 50 credits, he needed 8 more Fragmented Beast Cores or 40 credits worth of loot.
He turned around to survey the safe zone.
Initiates were panicking. Many were bandaging deep gashes from the Iron-Jaw Scavengers. Others were trying to barter with each other, holding up rusty iron broadswords or wooden staff starters they didn't know how to use properly.
"Selling Iron Broadsword!" a large man yelled near the pillar. "Iron Tier! Looking for healing potions or food!"
Leo walked toward the edge of the market area where wounded people were sitting against the slate rocks.
A young woman sat clutching her shoulder, blood seeping through her torn denim jacket. Beside her lay three Fragmented Beast Cores in the dirt, completely ignored.
"Hey," Leo said gently, crouching down a few feet away. "Are you alright?"
She looked up, eyes bloodshot and terrified. "My shoulder... one of those things clawed me. The shop sells healing salves, but they cost 15 credits. I only have 15 credits worth of cores, but I don't know how to sell them to the stone."
Leo pulled out the half-full bottle of aspirin from his pocket.
It was an ordinary bottle of over-the-counter painkiller from Earth. Non-living, non-magical, weighing less than 100 grams.
"This won't heal a deep monster wound," Leo said honestly, holding up the bottle. "But it will stop the fever and dull the pain completely within twenty minutes so you can rest until the next wave."
The woman looked at the clear plastic bottle like it was pure gold. "Please... I'll give you all my cores. Just make the pain stop."
Leo handed her two aspirin tablets and a splash of water from her own canteen.
She swallowed them desperately. Within moments, the tension in her jaw relaxed as the painkiller began to take effect. She pushed her three cores toward Leo.
"Take them," she whispered.
Leo picked up the three cores. "If you need more help before the next wave, stay near this pillar. It's safe here."
Gained 3 Fragmented Beast Cores.
Leo didn't feel guilty. He gave her real relief using standard Earth medicine, and in return, he gained 15 credits worth of raw inventory.
He spent the next two hours repeating this process across the camp.
He didn't scam anyone. He offered simple, practical Earth items—aspirin for pain, clean dry bandaging scraps, and dry meat—in exchange for raw beast cores that terrified survivors didn't know how to trade efficiently.
By the end of the second hour, Leo returned to his quiet corner under the slate rock.
His pocket contained 9 Fragmented Beast Cores and 10 System Credits.
Total liquid value: 55 System Credits.
Leo walked straight back to the glowing monolith, tapped the interface, and deposited 8 of his Fragmented Beast Cores.
Eight Fragmented Beast Cores sold.
Gained 40 System Credits.
Current Credit Balance: 50 Credits.
Leo didn't hesitate. He opened the raw materials store, navigated to the Energy Materials section, and selected the item he had been staring at for hours.
Purchase Confirmed: 1 Low-Grade Energy Crystal.
50 Credits deducted.
A brilliant blue, diamond-shaped crystal materialized in his palm. It was cold to the touch, humming with concentrated ambient energy. It weighed roughly 100 grams.
Leo walked back to his dark cave nook, sat down against the cold stone, and closed his eyes.
He held the Low-Grade Energy Crystal in his left hand.
Status Check.
Health: 100 out of 100.
Mana: 50 out of 50.
"Phase one complete," Leo whispered, his heart hammering in his chest with terrifying anticipation. "Now let's see if the system can handle infinite math."
He focused his mind, bypassing the automatic skill timer, and manually forced 49 points of Mana down his arms directly into the blue crystal.
Manual Skill Overclocking.
Material Replication.
A blinding flare of sapphire light consumed his hands.