"Exactly at 100 meters!" Ren announced as they headed toward the tunnel he used for his habitual escapes. His mushrooms pulsed with excitement, casting dancing shadows on the rough walls. "The perfect entrance."
"Perfect for what?" Min asked, but Ren was already turning at the familiar corner.
"This way," Ren didn't answer and slipped through an opening so narrow that Min had to hold his breath to pass.
"How did you even find...?" Taro stopped at seeing the network of tiny tunnels stretching before them. "Oh. So this is where you always sneak off to."
"Sorry," Ren laughed while advancing through a passage that seemed specifically designed for someone his size. "It's just..."
"It's just that you didn't want us following you to your secret vein to keep all the crystals for yourself," Min completed the sentence, his snake hissing with mild indignation.
"Not really, it's because you would..."
A distant sound, like claws against stone, made them all freeze.
"What was...?" Taro began, but Ren silenced him with a gesture.
They advanced silently until reaching a crack in the floor. The darkness emanating from it seemed deeper, more threatening than that of normal tunnels.
"My secret route," Ren whispered, his mushrooms pulsing softly. "I've been going down here every day."
Min peered into the abyss. "But... the monsters..."
Another sound, like something dragging itself across stone.
"You guys don't know how to avoid the worms... one wrong step and you attract them," Ren nodded. "That's why I couldn't bring you before, but now we are stronger."
Taro and Min exchanged looks.
How had Ren managed to spend an entire semester moving among monsters without being detected? The question hung in the air, but neither dared to ask it for a long explanation here.
"We'll go down to two hundred meters," Ren began descending through the crack with the familiarity of someone who has made the journey dozens of times. "That's where I need your help, Taro."
The descent was tense. Every brush of clothing against stone seemed amplified in the darkness. The tunnel twisted like a snake, sometimes so narrow they had to move sideways.
But Ren was super happy that the mana didn't feel as oppressive anymore.
"Living tunnel beetles like yours start at three hundred meters," Ren explained when they finally reached their objective. "Which means..."
"That if we make a tunnel here," Taro completed, his eyes gleaming with understanding, "and coat it with my Living Tunnel's crystal..."
"The lesser worms won't be able to enter," Ren nodded. "The crystal is too hard for them."
"It'll be a safe tunnel..." Min understood.
"And better yet," Ren smiled while his mushrooms pulsed with anticipation, "they'll think a lower-level creature was expelled and is hunting due to lack of mana. No common monster will risk entering once it's finished."
"Are you sure about this?" Taro asked.
"Completely," Ren pointed toward the school's direction. "I can feel the ruins more clearly here. We just need a direct path..."
"A secret tunnel," Min whispered. "Straight to whatever's under the school."
Ren guided them to another "slide" that led to a solitary zone at 200 meters and asked them not to move to avoid vibrations, while he decided for the perfect location.
"That's a good place to start," Ren manifested his hydra, its crystalline scales gleaming with his mushrooms' light in the darkness. At his side, Taro's Living Tunnel emerged in all its glory.
The two beasts began excavating with supernatural efficiency.
"Taro!" Ren called without stopping coordinating his hydra's movements. "Have your beast start coating the walls! The worms won't take long to notice the vibration!"
Min moved nervously while watching the first meters of tunnel form. "Shouldn't we...?"
"Don't be scared!" Ren smiled without taking his eyes off the work. "Just stay still and summon your snake! It can help us soon."
The water snake materialized, its scales shining with a deep blue tone in the tunnel's gloom.
"My hydra and your snake can keep the worms at bay while the beetle secures the first sections," Ren explained while the beasts continued their labor.
Twenty meters of tunnel later, Ren visibly tensed. His mushrooms pulsed once, catching something.
"First one's coming!" he warned. "Taro, stop excavating! Start the blockade!"
The Living Tunnel immediately changed its task, living crystal flowing from its segments to strengthen the walls.
Ren guided his hydra a few meters beyond the finished tunnel's end. "Here it comes!"
The earth trembled beneath the hydra. A common worm, its segmented body glowing with a sickly tone, emerged from the wall as if it were water.
"Diamond Shield!" Ren ordered.
The hydra's scales shone intensely, crystallizing into an improvised armor.
'Not as hard as it will be at higher ranks,' Ren thought, 'but it'll do!'
The worm launched itself at the hydra, only to find its jaws trapped by the crystalline beast.
"Min!" Ren called. "Now!"
The water snake slid swiftly, coiling around the worm. Between the two beasts they began pulling, dragging the monster completely from its hole.
The worm writhed uselessly, trapped between the hydra's jaws and the snake's constricting coils.
"Just a bit more and...!"
The Living Tunnel, apparently tired of waiting, simply crushed the worm with one of its enormous feet.
"Well..." Ren blinked in surprise. "That... works too."
"Can we get back to work?" Taro asked while his beast casually cleaned its foot against the wall. "I'd prefer to finish before more come."
"Right!" Ren had his hydra return to excavating. "But stay alert! Some worms are foolish enough to..."
He broke off, his mushrooms pulsing again.
"From the right!" he warned.
The beasts positioned themselves, prepared for another round.
Luna's cousins looked at each other in horror when the first rays of sun woke them.
They had fallen asleep after a night of 'planning surveillance strategies' with their cousin.
They ran through the hallways, trying to maintain aristocratic composure. But when they reached Ren's room, they found the door closed and no sound from within.
"Did he escape us?" the blonde bit her lip. "Great spies…"
As if answering her question, Liu appeared turning the corner, muttering to himself while walking distractedly.
The cousins exchanged a look and slid silently closer, hiding behind a column.
"...and now with that ruins thing..." they managed to hear Liu. "...as if the hydra wasn't enough..."
The blue-haired cousin barely contained an exclamation. Her companion covered her mouth with one hand.