Nova barely had time to take a breath. One moment she was stepping out of a chamber; the next, the stone behind her rippled and sucked her forward, hurling her into another trial before she even steadied herself. She hit the platform with a sharp gasp, vision spinning.
Fin was dragged through a heartbeat later, the wall spitting him into the chamber with brutal force.
"Nova!" He caught her immediately, pulling her into his arms. He kissed her hard, relief flooding through the matebond in a warm, buzzing wave that steadied both of them.
She grinned, breathless. "Did you miss me?"
"Yes," he said without hesitation.
The floor vanished.
An abyss of drifting aether yawned beneath them, swirling with colors she had no mortal language for — starfire, shadow, and magic so ancient it felt alive. Nova and Fin stood on a single stone platform suspended over nothing. The tile was barely large enough for one person; Fin anchored himself behind her, hands on her waist to steady them both.
Before them, dozens of floating platforms hovered in an arc across the void, each one etched with shifting symbols — calculus fused with alchemic arithmetic.
At the far end of the chasm, an obsidian dais rose like a throne carved out of night. Beneath it, carved into spiraling runes that glowed with a heartbeat:
ONLY THROUGH CHANGE MAY BALANCE BE KNOWN.
SOLVE THE LIVING EQUATION, OR BE UNDONE.
Nova exhaled slowly, bracing herself against the stone wall. Her head throbbed so viciously she winced. It felt as if someone had slid a blade behind her eyes and twisted. The magic inside this chamber gnawed at her nerves, testing the edges of her strength like a living creature tasting blood.
Fin leaned in and pressed a kiss to her temple. "Baby, your head... It's been bad."
She tilted slightly toward him, the smallest surrender. "You feel it again?"
"Hard not to," he murmured, his voice tight with the effort of hiding how much it hurt.
"I'm sorry you're feeling it too," she whispered, squeezing his hand — apology, concern, and tenderness tangled together.
Fin breathed love into her through their matebond, warm and steady, wrapping around her like a shield. He kissed her forehead again, lingering. "It's okay, baby."
"Is there a way for me to block that from you?" she asked softly, voicing the thought that had haunted her earlier too. "I don't want you to hurt like this."
Fin's stomach clenched. Yes — there was a way. A technique to block your feelings from your mate. But he would never tell her. He prayed the gods themselves would hide whatever book may have that information.
"No," he said gently, lying without a flicker of hesitation. "And even if there were, I wouldn't want that, Nova."
She looked at him with such raw worry it almost gutted him.
Fin guided her closer, brushing his thumb along her cheek. "Elias's tonic and Vaelthorn root helped, right?"
"Yes," she breathed, though her voice quivered beneath the pain.
She turned around fully, pressing her back against his chest and fitting herself beneath his chin. It grounded her.
Fin looked over her shoulder at the impossible expanse before them. "Is there—gods—a set number of puzzles we have to solve?"
"I think so," Nova said. "I only got fragments of a vision from the book this morning."
Fin let out a breath half disbelieving, half amused. "You read that book so fast."
Nova blinked. "I didn't read it. I touched it. I saw a vision."
"Well, to us, you flipped pages faster than wind. I thought that was… normal for you." He rubbed his thumb along her hip. "I wondered if you always read that way."
She exhaled a faint laugh. "I didn't realize that."
"Jax said you did that last time too."
"Oh." Nova smiled. "That explains a bit."
Fin dipped his head, brushing his lips along the side of her throat. "Let's solve this so I can take you home."
She grinned despite the pounding in her skull. "Motivated, are we?"
"I want to take a bath with you," he murmured into her skin.
Nova giggled, turning her head to kiss his shoulder. "That is my favorite thing to do."
The chamber disagreed with giving them a moment.
A towering wall of glowing runes erupted across the void, expanding outward like a living tapestry. Symbols rearranged themselves at dizzying speed — derivatives, integrals, alchemic ratios, magical constants folding into one another faster than blinking.
Fin stared. "Tell me that's not calculus."
Nova lifted her head, eyes narrowing at the shifting symbols. "It's worse."
"How worse?"
"Mixed with alchemy."
Fin groaned. "Of course it is."
Nova squared her shoulders and studied the massive equation forming before them as their first platform began to hum beneath their feet.
"Alright," she whispered. "Help me think this through."
Fin tightened his arms around her, steadying her against the sway of the platform. "I'm with you. Talk me through this."
She swallowed, fighting the stabbing pain in her skull.
"I see the derivative of a three-term alchemic function," she murmured. "Aether, Ignis, Terra… all blended with x."
Nova breathed in, braced herself against him, and whispered—
"Three Aether x squared…"
"And Ignis becomes negative with x to the negative second," Fin continued, catching the rhythm with her.
"And Terra divides into x," she said.
"Then that's our answer." Fin nodded at the glowing tiles.
Nova scanned them rapidly, heartbeat quickening.
"There."
Fin kissed the back of her neck. "Then take us there."
She stepped.
The platform locked.
The chamber roared.
They continued across platform after platform, solving derivative after integral with brutal precision. Fin stayed pressed to Nova's back the entire time, anchoring her as the tiles shifted beneath them in dizzying rotations.
"There—negative sign," Fin caught quietly as the symbols reshaped.
Nova nodded. "I see it. That changes the entire expression."
"Then change it back," he murmured against her ear.
She giggled.
Together they stepped from answer to answer, the abyss swallowing every mistake around them. Every correct platform locked into place. Every wrong one detonated behind them. They never stepped wrong.
Finally they'd reached the last equation ignited across the void, enormous, shifting faster than human sight could track.
Even Fin inhaled sharply.
"Nova… I don't think this one wants to be solved." Fin said, brows furrowed.
"It does," she whispered, eyes narrowing. "Just not with numbers. It is aetheric."
∫ f(x, Aether, Ignis, Terra, Void) dx
SOLVE NOT FOR VALUE.
SOLVE FOR BALANCE.
Her breath stalled.
The platforms began to move. The abyss pulse. The symbols swirled violently, rearranging themselves like a living organism trying to devour her.
Fin's arms tightened around her waist.
She would have laughed if not for the pain stabbing behind her eyes.
"This equation doesn't seek a number," she whispered. "It seeks equilibrium. But I think we need to use magic to solve this."
Gold poured from Nova's palms, pulling from Fin's magic.
Aether's violet shimmered like starlight.
Ignis burned hot.
Terra anchored her breath.
Void pulsed cold at the edges.
And the relentless ache in her skull stitched through them — a raw, unfiltered reminder that she still stood.
She wove the elements together with exquisite precision. She shaped them into one perfect form — a sigil of equilibrium, bright and alive.
Then she thrust it forward. The abyss stilled. The platforms aligned into a straight bridge of light beneath her feet.
Nova walked, each step steady despite the knife of pain carving through her skull.
The dais opened. The crystalline core drifted toward her and settled into her palms without burning.
"We did it," she said smiling.
But her headache — gods — it felt as though the calculus had been carved directly into her bones.
And the temple had not finished with her.