She only knew of two things that could drain a sorcerer that fast. A fatal injury, or a lethal binding vow.
"Mai," Maki said, the word cutting sharply through the quiet woods.
She shoved her bare hand deep into her coat pocket and yanked out her phone. The screen was black. She held down the power button, pressing it until her thumb ached. Nothing. The battery had died a long time ago, and even if it hadn't, there wasn't a single bar of service out here in the mountains anyway.
"Damn it."
She shoved the dead plastic back into her pocket. The rush of the sudden power upgrade completely vanished, replaced by a tight, heavy knot in her chest.
The silence of the woods felt mocking. She was completely cut off, standing in the middle of nowhere while her sister might be bleeding out.
She gripped the naginata with both hands. She raised the heavy wooden polearm and slammed the blunt end down into the frozen earth.
She just wanted to hit something. she didn't even put her full weight behind it, but the impact sounded like a mortar shell detonating.
A massive shockwave blasted the snow away in a perfect circle. Deep, jagged fissures shrieked across the solid ice, spiderwebbing out from the base of her weapon in all directions.
Maki froze, staring at the cracks.
A deep, structural groan echoed from right beneath her boots.
Before she could even shift her weight, the forest floor gave out.
The ground simply opened up and swallowed her. Maki dropped into empty air, surrounded by hundreds of pounds of collapsing ice and frozen dirt. She plummeted into the dark, twisting her body on pure instinct.
She hit solid rock hard. She tucked her shoulder, rolling to bleed off the massive momentum, and skidded across a smooth stone floor.
Snow and dirt rained down on her from the jagged hole thirty feet above.
Maki stayed on one knee, gripping her weapon. She blinked, coughing as the dust settled, and looked around.
She wasn't in a dirt cave.
Faint, pale blue light pulsed slowly from the walls. She was kneeling in the middle of a massive, perfectly carved stone corridor, buried deep underground. The air down here felt heavy, thick with the distinct, oppressive hum of a high-level barrier.
She looked up at the hole she had just accidentally punched through solid bedrock, then looked down at her bare hand.
"You've gotta be kidding me," she muttered.
Maki pushed herself up, brushing a clump of freezing dirt off her shoulder.
She walked forward, her boots echoing sharply against the smooth stone. The pale blue light seeped from the carved masonry, casting long, warped shadows ahead of her. The air was stale, completely devoid of the sharp pine scent from the surface. It smelled like ancient dust and stagnant cold.
"Place feels like a damn tomb," she muttered, her voice bouncing off the high ceiling.
She didn't slow down to admire the architecture. If this was the vault holding the Eight-Fanged Sword, she was going to grab it and immediately find a way back to the surface. She needed a working phone.
The corridor opened up into a wide antechamber, ending abruptly at a set of massive, floor-to-ceiling doors. They were carved from solid granite, completely seamless, without a handle or a lock in sight. A thick layer of dust coated the stone, untouched for centuries.
Maki walked right up to the center seam, pressed her bare left palm flat against the granite, and shoved.
The stone shrieked.
Decades of sediment broke apart in a cloud of gray dust as the massive slab gave way. Maki barely even leaned her weight into it, but the granite swung inward with a heavy, grinding scrape, yielding to her hand like a cheap wooden gate.
She stepped through the dust cloud and into the dark.
...
Mai lay flat on her back, staring at the ceiling of her Kyoto dorm. Her hands still smelled faintly of harsh solvent and gun oil. Utahime hadn't been bluffing—she had spent the entire previous evening and most of this morning scrubbing every single blade and rifle in the armory.
She closed her eyes, just wanting to sleep.
A weird, cold flutter sparked right behind her ribs.
Mai frowned in the quiet room. She pressed the heel of her hand flat against her stomach. It didn't feel like nausea. It felt hollow.
She held up her right hand and concentrated, trying to pull a basic, tiny spark of cursed energy to her fingertips. Usually, her energy felt like a heavy, sluggish weight she had to forcefully drag to the surface.
This time, the energy sparked, flickered violently, and just vanished.
Mai sat up.
She tried again, pushing harder. The energy pooled for a fraction of a second, then immediately slipped away, like water pouring straight through a cracked glass. Her internal reserves were dropping. Not burning out from using her technique. Draining.
"What the hell," she whispered.
She checked her arms, pulled the collar of her shirt down to check her chest. Nothing. No curse marks, no injuries, no lingering effects from a fight. Just a steady, quiet siphon actively pulling her energy out of her body.
There was no logical reason for it. Unless it had something to do with the only major thing that had changed in her life twenty-four hours ago.
She snatched her phone off the nightstand. She bypassed Utahime and Principal Gakuganji, pulling up Ren's contact, and hit dial.
It rang twice. The muffled, echoing announcements of a busy Tokyo train station bled through the speaker.
"Miss me already?" Ren asked, his voice smooth and entirely unbothered.
"What did you do to me?" Mai demanded. She swung her legs off the mattress, gripping the phone tight enough to make the plastic creak.
"Good morning to you too," Ren said. "I'm currently standing outside Shibuya Station with Nanami. Want to narrow that accusation down a bit?"
"I'm not joking, Ren. My cursed energy." She stood up, pacing the short length of her dorm. "It's just... leaving. It's leaking out of nowhere. I can't hold a single spark."
Ren stopped walking. He drifted toward a concrete pillar, letting Nanami, Megumi, and Nobara move a few steps ahead into the morning commuter rush.
He pulled the phone away from his ear and tapped the mute button.
He stared blankly at the ticket gates. The System had explicitly stated it was using Mai's natural signature as a siphon. It hadn't said a single word about taking hers.
"System," Ren muttered under his breath.
A translucent blue panel snapped into existence, hovering faintly over the blur of passing business suits.
"What the hell did you do?" Ren whispered, keeping his back to Nanami and the others.
"Explain why her energy is dropping."