Apocalypse Architect: A Tower Defense LitRPG

Chapter 66: Upgrading to Tier 2 Sentry Tower

Gareth’s miraculous recovery boosted morale, but it also served as a sobering lesson. No one was stupid enough to stand in the Black Rain again. The allure of Awakening was strong, but the fear of a meaningless, fever-wracked death was stronger.

That night, Jax hit a resource windfall.

A standard System mission dropped a hundred units of Refined Iron. Minutes later, he cashed in a Bounty Protocol for another hundred units of Stardust Stone.

“Finally,” Jax muttered, looking at his inventory. “No more scraping by.”

He had 120 Stardust Stones and 100 Refined Iron. It was time to spend.

He walked to the nearest Sentry Tower, the rain drumming against his raincoat. He placed his hand on the cold metal structure.

“Tier 2 Upgrade. Execute.”

A geometric grid of blue light enveloped the tower, humming with energy. The structure began to reconfigure itself, plates shifting and interlocking with mechanical precision.

Ten minutes later, a chime echoed in his mind.

[System: Tier 2 Sentry Tower Upgrade Complete.]

Jax pulled up the specs.

[Tier 2 Sentry Tower] [Attack Power: 200] [Range: 100m] [Fire Rate: 1.0/sec] [Integrity: 200]

“Damn,” Jax grinned. “It’s literally double everything. One of these is worth two Tier 1s.”

He didn’t hesitate. He moved to the second tower on the perimeter and dumped the rest of his resources into it.

[System: Tier 2 Sentry Tower Upgrade Complete.]

Now, the fortress bristled with serious firepower. Doubled damage, doubled range, doubled speed. The Rodent-Maw Creepers weren’t just going to be repelled; they were going to be erased.

That evening, the team gathered in the common room, anxiety etched on their faces.

“Relax,” Jax said, leaning against the wall. “Same drill as last night. Two waves.”

“Is this the new normal, Boss?” Silas asked, sharpening his spear. “Double waves every night?”

“Probably,” Jax shrugged. “The difficulty curve is ramping up. I’ll let you know if it changes.”

“Fair enough,” Silas sighed. “We’ve given up on the Awakening lottery anyway. But… when can we buy some of that juice you gave Gareth?”

Kaleb nodded eagerly. “Yeah, look at him. He’s a machine.”

Since recovering from the fever, Gareth had been tearing through his workload. He was mining ten Energy Shards a day without breaking a sweat—matching Silas’s best numbers and looking ready for more. The team was convinced Jax had fed him some kind of super-soldier serum.

“That wasn’t a vitamin shot,” Jax said dryly. “It’s an Augmentation Serum. And it costs one hundred Cores per dose. You got that kind of cash?”

Silas and Kaleb froze. One hundred Cores was a fortune.

“That expensive?” Silas slumped. “Forget I asked. But if I get sick, do I get one on the house?”

“Nope,” Jax replied, deadpan. “If you get sick, I’ll build you a coffin. Hand-carved. Real nice wood.”

“Wow,” Silas muttered. “Cold, Boss. Ice cold.”

“It’s not cold, it’s reality,” Jax said, his voice hardening. “Don’t count on miracles. I treated Gareth like a dead horse—risked a desperate cure because he was dying anyway. It wasn’t cold medicine; it was a gamble. If his body had rejected it, he’d be in the ground right now.”

The room went silent.

“But,” Jax added, softening the blow, “if you work hard… maybe one day I’ll make you something stronger than an Awakened.”

Kaleb’s head snapped up. “Stronger? Is that even possible?”

“We’ll see,” Jax smirked. “Now get to work. Two days until the weekend. Silas, you’re heading back to the city then. I need intel on the Helios Syndicate.”

“On it, Boss.”

The next day, the Black Rain continued to fall, turning the sky into a bruising shade of charcoal. Lightning arced through the clouds, silent and ominous.

Silas and Gareth were already down in the extraction pit. Kaleb, having finished processing the insect corpses, stood next to Jax, fidgeting.

“Uh, Boss?” Kaleb scratched his head. “Maybe I should go dig too?”

Jax raised an eyebrow. “You serious?”

“Yeah. It feels… wrong. Watching them work while I just stand here.”

“Let me check the slots.”

Jax pulled up the base management interface. He could technically build another Extraction Well, but his labor force was maxed out. Still, with the rain showing no sign of stopping, energy consumption was going to spike. He needed a surplus.

“System, cost for a new Extraction Well?”

[Construction Cost: 100 Refined Iron, 100 Stardust Stone.]

“You’ve got to be kidding me,” Jax groaned. “That’s the same price as a Fortress upgrade. Is there a mine for these materials?”

[User can locate Resource Mines via Bounty Protocols.]

“Mines…” Jax’s eyes lit up. If he could secure a dedicated source of Refined Iron and Stardust Stone, the resource bottleneck would disappear.

He looked back at Kaleb, who was waving a hand in front of his face.

“Hello? Earth to Boss?”

“Sorry,” Jax said. “No open slots right now. You’re benched.”

Kaleb let out a breath he was holding. “Oh, thank god.”

“What?”

“I… wasn’t actually ready to dig,” Kaleb admitted sheepishly. “Just felt like I should offer.”

“Don’t worry,” Jax laughed. “Your time will come.”

He decided to hold off on the new Well. He needed to stockpile resources first. Assigning Annie to the mines felt wrong, and putting Barnaby down there would likely trigger a berserker rage from his sister, Elena, if she ever found out.

Evening brought the Sandworms.

A massive swarm churned the mud outside the canyon entrance. Jax watched them, feeling nothing but calculation.

He decided to test the new towers. He left the Howitzer Turret offline and funneled power to the Sentry Towers.

[Mission: Annihilate all Tier 1 Sandworms.] [Reward: Howitzer Turret Upgrade Permission.] [Penalty: Builder Level -1.]

“Annihilate?” Jax frowned. “That implies zero escapees.”

Normally, he just thinned the herd until they retreated. Total extermination was a different beast.

“Listen up!” Jax barked. “Change of plans. We need a full wipe tonight. Nothing leaves alive.”

The team looked at the writhing sea of worms. “All of them? Boss, if they rout, we can’t chase them down.”

“I’ll take the main entrance,” Jax said, pointing to the choke point. “You guys cover the valley mouth. Seal the exits.”

It was a containment operation.

Barnaby stepped forward, reaching for his weapon. “I help Jax.”

“No,” Jax stopped him, placing a hand on the giant’s chest. “Barney, I need you on the wall. Watch the towers. Only reload the Energy Shards when I give the signal. Understand?”

Barnaby hesitated, looking torn, but he saw the steel in Jax’s eyes.

“Okay,” Barnaby nodded solemnly. “I watch tower.”

“Good man.”