The first level of the sewer was relatively ordinary. Other than the sound of flowing water, the only noise was the echo of their footsteps. Huarui seemed quite familiar with this level and purposefully led the group forward. Eventually, he stopped in front of a wall.
"This is it—an hidden door," Huarui announced, pointing to a small notch at the top of the wall.
"That notch is his marker," Hachi explained. "He claims every stone in these ancient walls is full of cracks and holes, so no one would notice if he made another small one. And every notch is unique…"
Phyllis was speechless. What if one day his marker crumbled and he couldn't find the door anymore?
Huarui pushed the door, which turned silently on its hinges without any apparent mechanism. The group entered, finding a staircase descending into darkness.
"This door is too plain, so the next level is also pretty ordinary," Huarui remarked, clearly familiar with what lay ahead. "But from the next level onward, there are trapdoors. If you accidentally step on one, you might get teleported to another layer. And trust me, none of those places are pleasant—it's all disgusting mutated rats and venomous snakes. Stay close. If we get separated, at least we can regroup quickly."
Phyllis nodded in agreement. The second level was known for its hidden random teleportation arrays embedded in the floor tiles' intricate patterns. Each tile contained a unique design. As a specialist in spatial arrays, she could easily avoid them, but Huarui had clearly learned the hard way.
Huarui's Summoned Ice Demon
As they descended further, Huarui summoned his Ice Demon, a mid-tier demon with a humanoid upper body and a fish-like tail. Native to polar regions, it possessed innate Tier 3 ice magic and Tier 6 water affinity, making it a prized companion for combat magicians.
Mid-tier demons had their drawbacks, however. Despite their powerful magic, their stamina was limited; three to five spells would deplete them. Their range was also short, typically no more than 50 meters, meaning they couldn't stray far from their summoner. On the plus side, such demons required little to no sustenance due to their dormant state when not in use. However, their intelligence was rudimentary, functioning solely to obey commands.
Although the current challenge was sewage water, Huarui confidently instructed the Ice Demon to handle it. With a gesture, the demon redirected the murky water upward, forming a steady stream into the ceiling's trough while keeping the main pipe empty.
"I suspect the sewer system has monitoring mechanisms, like pressure pumps. If water flow becomes obstructed, it might trigger an alarm," Huarui noted.
"A short blockage should be fine," Phyllis replied. "Freeze the outflow for a few seconds. That's all I need."
"Just a few seconds?" Huarui looked incredulous but gave the order.
The outflow froze, leaving a meter-high vacuum in the pipe. Phyllis swiftly inserted her perception stone into the opening, examined the view, and withdrew it. "Done!" she announced, activating a levitation spell to float out of the pool as the flow resumed.
Back on dry ground, Phyllis began sketching a teleportation array.
"Unbelievable! Just one glance!" Huarui exclaimed. "What did you see?"
"Rats," Phyllis said grimly. "Red-eyed, mutated rats. The entire floor is crawling with them."
Huarui and Hachi exchanged glances. "Looks like we've reached the same layer as last time…" Huarui murmured. "By the way, what level are we even on?"
Phyllis shrugged. "The pipe network doesn't follow a clear vertical layout. Who knows where we are? But judging by the increasing sewage density, we're probably nearing the bottom."
"But we still haven't found any remnants of the scapegoat array…" Huarui sighed.
"Maybe it wasn't placed in the sewers," Phyllis suggested.
"No," Huarui insisted, "if it were me, I'd definitely place it here. Now I'm even more certain—the culprit is an expert! Only a master would set the array in the deepest, most inaccessible layer. The closer we get to the core, the more likely we'll find something."
What terrifying logic… Phyllis thought, rubbing her temples.
"Prince Huarui, what makes you think we can reach such depths?" Hachi scoffed. "Isn't this a little too ambitious?"
Huarui dismissed the doubt. "We're a formidable team—a Tier 3 spatial theory prodigy, a Tier 5 combat magician, and you, a Tier 5 squire paladin. Together, we can handle a mere planar summoner!"
Phyllis mentally filed away Hachi's rank, confirming her suspicion that he was a squire paladin trained by the Church of Light. Unlike full paladins, he hadn't undergone the formal consecration ceremony, which allowed him to retain his autonomy from the Church.
Despite Hachi's reservations, Huarui's insatiable curiosity left no room for retreat. Reluctantly, the group advanced. Phyllis finalized the teleportation array and warned them about the mutated rats' dangers.
"They're primarily physical attackers, but they swarm in packs. Also, avoid getting scratched—the water here is toxic and could cause severe poisoning."
They teleported into the heart of the rat swarm. Huarui's Ice Demon immediately unleashed a freezing spell, immobilizing the creatures. Phyllis followed up with a Tier 3 Wind Blade Scroll, shattering the frozen rats into fragments.
With the path cleared, Phyllis surveyed the vast, glowing chamber ahead. Beneath their feet, fluorescent sewage formed a shimmering stream, casting an eerie light.
"This is the reaction pool," Huarui explained. "It's designed to let waste liquids interact and neutralize before they're processed for recovery."
"Seems you've done your homework on alchemical wastewater treatment," Phyllis remarked dryly.
"Of course! I'd never risk my goddess's safety without thorough preparation," Huarui replied smugly.
Ignoring his theatrics, Phyllis focused on the environment. Hachi voiced a practical concern: "We shouldn't wander too much. If your Ice Demon can only cast one more spell, we'll be defenseless."
"Fair point," Huarui conceded, sketching a new summoning array on the ground.
Phyllis watched curiously as hundreds of black shapes emerged from the array. They spread out, flying and crawling across the chamber.
"Cockroaches!" Phyllis screamed, retreating behind Hachi.
Huarui looked wounded. "Why him and not me? Am I not trustworthy?"
"Saints' shields are always the safest," Hachi quipped.
"Get away from me, you cockroach boy!" Phyllis snapped.
Undeterred, Huarui explained, "Cockroaches are invincible—immune to all magic, resistant to physical attacks, and capable of reaching places no one suspects. Perfect spies!"
"And yet, a single stomp can crush them," Phyllis retorted.
Unfazed, Huarui summoned a giant cockroach marked with a glowing blue pentagram—a Hexides, a rare mental magic parasite known for its extraordinary scouting abilities.