Chapter 16: The Calculus of Mana Regeneration
The morning sun filtered through the heavy velvet curtains of Ren's bedroom, casting a warm, golden glow across the massive four-poster bed.
Normally, by this hour, the manor was bustling. Elara would be coordinating the cleaning schedule, Lyla would be hauling firewood, and Kira would be shadowing Ren. Today, however, the manor was eerily quiet.
In the center of the oversized bed, buried under a mountain of pearlescent silk sheets and goose-down comforters, a tangle of limbs, a silver tail, and two bovine horns shifted restlessly.
Ren sat in a plush armchair near the hearth, sipping a cup of hot black tea. He had been awake since dawn, quietly observing them.
"Ugh..." Elara groaned, her brown hair a tangled mess as she peeked out from under the covers. She tried to sit up, but her arms trembled, and she immediately collapsed back into the pillows. "Ren? Why does my blood feel like lead?"
At the sound of Elara's voice, Kira whimpered, burying her face deeper into the mattress. Lyla didn't even wake; the massive cow-girl was snoring softly, taking up more than half the bed, her face pale.
"Don't force it, Elara," Ren said softly, setting his tea down and walking over. He sat on the edge of the mattress, gently pushing a strand of hair out of her eyes. "You're experiencing mana starvation."
"But... we ate so much last night," Elara whispered weakly, remembering the mountain of roasted boar and ice cream Ren had fed them after the hot spring.
"Your stomachs are full, but your mana circuits are empty," Ren explained, his tone soothing but analytical. "Last night, the System forcibly evolved your classes to Mythic tier. When that happened, your maximum mana capacities expanded exponentially. Your 'containers' are now massive. But your biological regeneration rate hasn't caught up. You are running on empty tanks."
Elara frowned, her sharp mind trying to process the logic through the heavy brain-fog. "The tutor said mana recovers at a flat rate. Five points an hour."
Ren scoffed lightly, walking over to a silver cart he had wheeled in earlier. He lifted the cloche, revealing a stack of warm, honey-glazed pastries and a pitcher of freshly squeezed fruit juice.
"The tutor is a fool who doesn't understand calculus," Ren said, bringing a plate over and helping Elara sit up against the headboard. "Nothing in the universe moves at a flat rate, Elara. Rates of change are dynamic. They depend on variables."
He handed her a pastry, which she took with trembling hands, taking a small bite. The sugar instantly helped her focus.
"Mana regeneration is basically osmosis," Ren continued, breaking off a piece of a pastry and gently popping it into Kira's mouth as the sleepy fox-kin cracked an eye open. Kira chewed lazily, purring as Ren rubbed her ears.
"Osmosis?" Elara asked.
"The movement of a substance from an area of high concentration to an area of low concentration," Ren explained. "Your bodies are currently low-concentration zones. The ambient air in this room is normal concentration. So, the mana slowly trickles into you. The rate of change—the derivative of your recovery—is bottlenecked by the pressure difference."
"So... how do we fix it?" Lyla mumbled. The heavy girl was finally waking up, looking absolutely mortified to be sleeping in the Young Master's bed. "I'm sorry, Master Ren... I should be working..."
Ensure your favorite authors get the support they deserve. Read this novel on NovelFire.
"You are working. You're recovering," Ren corrected firmly, handing Lyla a massive pastry, which she held delicately in her large hands. "And we fix it by changing the atmospheric pressure."
Ren stood up. He didn't just want them to recover; he wanted to permanently increase their intake bandwidth.
He walked to the four corners of the bed. At each wooden post, he pulled a small, flawlessly carved crystal from his pocket and set it down.
"Eat your breakfast," Ren instructed. "And take deep breaths."
Ren stepped back and channeled his own mana into the four crystals. He wasn't casting a spell; he was creating a localized hyperbaric chamber. He forcibly drew the ambient mana from the entire manor, compressing it, and trapping it exclusively within the confines of the four-poster bed.
To the girls, the air suddenly shimmered with a faint, iridescent blue light. The air felt heavy, but incredibly crisp, like the atmosphere right before a massive thunderstorm.
The high-density mana field crashed into their depleted, low-density bodies.
Elara gasped. It wasn't a slow trickle anymore. It was a flood. She could literally feel the energy rushing into her pores, filling the massive, empty void the Mythic class evolution had created. The leaden feeling in her blood vanished, replaced by a thrumming, vibrating power.
Kira sat bolt upright, her silver fur standing on end with static electricity, her amber eyes glowing brightly.
Lyla let out a long, shuddering breath, the color returning to her pale cheeks as her massive strength re-knitted itself.
"Calculus," Ren smiled, watching the color return to his vanguard. "By exponentially increasing the external concentration, we drastically steepen the rate of absorption. You aren't recovering at five points an hour anymore. You're recovering at fifty."
Elara looked at her hands. The exhaustion was completely gone. She felt stronger, sharper, and more alive than she ever had in her nine years of life. She looked up at Ren, who was watching them with that same warm, fiercely protective gaze.
She realized they were sitting in his bed, wearing his silk, eating breakfast he had prepared, breathing air he had purified and pressurized just for them.
"You really won't let us suffer even a little bit, will you?" Elara asked, a soft, helpless smile spreading across her face.
"Suffering is mathematically inefficient," Ren replied smoothly, walking over to collect their empty plates.
Before he could turn around, the heavy oak door of the bedroom swung open.
Martha stepped in, carrying a ledger. The Head Maid stopped dead in her tracks. She looked at the Young Master collecting plates, and then at the three girls lounging luxuriously in his bed, surrounded by a glowing field of high-density mana.
A year ago, Martha would have fainted from the sheer impropriety of the scene. Now, knowing what Ren was building them into, she merely sighed, closing the door firmly behind her to keep the servants' prying eyes away.
"I see the vanguard is recovering well, My Lord," Martha said smoothly, ignoring the fact that her own daughter was currently wrapped in the Lord's goose-down comforter.
"They are operating at peak efficiency, Martha," Ren confirmed, dispelling the mana canopy so she could approach. "Is there a problem?"
Martha’s professional mask slipped, revealing a deep frown. She looked down at the ledger.
"Yes, My Lord. A severe one," Martha reported. "The Baron is currently in a panic. The eastern river—the one that feeds the village crops and supplies our manor's plumbing—is drying up. The water level has dropped three feet since yesterday."
Ren’s dark eyes narrowed. Rivers didn't just dry up overnight unless there was a catastrophic geological shift. Or...
The stampede, Ren calculated instantly. The shifting mana densities in the Deep Woods are causing the local ecosystem to warp. The beasts are drinking it, or the ambient heat of a massive horde is evaporating the tributaries.
"If the river dries up, the village loses its winter harvest," Elara said, tossing the covers aside and sliding out of bed, her professional maid persona instantly overriding her pampered morning. "And we lose the hot spring and our indoor plumbing."
Ren's expression turned ice-cold. Threatening the village was a problem. Threatening the hot spring he used to pamper his girls was an act of war.
"Lyla, Kira, get dressed," Ren commanded, the warmth in his voice completely replaced by the crisp, authoritative tone of an Archmage. "Martha, tell my father not to send the guards. They will just get in the way."
"What are we going to do, Master Ren?" Lyla asked, quickly pulling on her boots.
Ren picked up a pristine white coat he had tailored for himself, slipping it on.
"We are going to go upriver," Ren said softly. "And we are going to teach whatever is blocking our water supply a very painful lesson in fluid dynamics."