Hogwarts: Lacus doesn't want to be a witch who destroys nations.

Underwater combat! Lux instantly experienced what hellish difficulty meant.

She wanted to shout "Petrify!", but as soon as she opened her mouth, the icy lake water rushed in, and the gill grass's filtration system couldn't handle so much water.

Lux could only shut her mouth, silently chanting the spell in her mind, while desperately concentrating her mind, and struggling to point her wand at one of the guards.

"They'll all be petrified!"

Driven by willpower, the tip of the staff struggled to glow with a faint light, and a beam of petrifying magic, several times weaker and much slower than on the shore, shot out.

The guard was clearly experienced; with a flick of his tail, he twisted his body with extraordinary agility in the water, sending the beam of light directly into the void, only creating a small splash.

Meanwhile, another guard's bone fork swept across.

Lux ducked awkwardly, the force of the bone fork sweeping across her head, cutting off a few strands of her golden hair. She felt the air in her lungs being consumed rapidly, and the burning pain from the gill grass seemed to be intensifying.

"No, the power is greatly reduced if I can't pronounce it aloud, and I can't concentrate on casting the spell at all." Lux was extremely anxious. Underwater, every movement and every spell she cast felt like struggling in sticky glue.

Using hand gestures and verbal commands is still too authoritative for wizards.

Lux can only rely on three mana-consuming skills to maneuver.

She released a translucent singularity in an attempt to disrupt the other party's vision, but the light was severely weakened and scattered underwater, so the effect was minimal.

A fierce chase and dodge unfolded around the altar, with Lux struggling like a small fish being chased by a shark.

The mermaid guard moved with ghostly agility in the water, the bone fork flashing past her again and again with a chilling glint of death. Each close dodge accelerated the loss of the gill grass's effects, making the burning pain in her throat clearer and her breathing more and more difficult, as if a huge rock was pressing on her chest.

"Glug glug..." She couldn't help but choke on the water, and the feeling of suffocation instantly overwhelmed her.

Lux doesn't have much time left.

The gills are losing function, and the blue bars are almost gone.

Looking at the altar that was so close yet so far, and at the runebook that radiated an alluring light, Lux's eyes flashed with a resolute determination.

"Let's give it our all!"

"Translucent Singularity! Binding of Light!"

She pointed her wand sharply at the waters in front of the altar and near the queen.

A dazzling ball of light exploded in front of the altar in an instant. The intense light was like a small sun even in the deep water, instantly causing all the mermaid guards to instinctively close their eyes or turn their heads away.

At the same time, Light Binding shot from the tip of Lux's staff, precisely binding the Queen and the two nearest guards.

The light bound their arms and fish tails, successfully creating a moment of chaos and stillness.

"Now!" Lux pushed off the rocks with both legs and charged towards the runebook at the top of the altar with all her might, like a barracuda.

She has only one goal: to unlock the secret manual.

"hiss--!!!"

The mermaid queen let out a furious shriek, the sound piercing through the water and carrying a terrifying pressure.

She clearly hadn't expected this intruder to be so audacious as to directly desecrate the sacred object!

Just as Lux's hand was about to touch the runebook that flowed with starlight, the Queen no longer hesitated. She suddenly stretched out her hand, which was covered with fine silver scales, and pressed it onto the runebook in the center of the altar!

She did not want to seize it, but rather to use the power of "divine grace" to drive away this blasphemer!

Om-!

The unsealed manual instantly burst forth with unprecedented brilliance, and an indescribable energy fluctuation, seemingly originating from the rules themselves, swept out.

At the Queen's fingertip, a crimson, molten-hot spot of light suddenly lit up.

The next second, the crimson dot seemed to come alive, instantly traversing space and precisely imprinting itself on Lux, who was sprinting at full speed.

"Ugh—!"

Lux felt as if she had been thrown into a steel furnace. Her vision went black, and she almost fainted.

His body froze instantly, and his sprint came to an abrupt halt.

[Affected by Ignite: Health is continuously decreasing. Semi-digital mode has been activated, so you will not experience the burning pain caused by Ignite.]

Lux turned around with difficulty and saw the Mermaid Queen staring at her with cold eyes, as if she were looking at a dead person.

More guards have broken free from the light's restraints and are trying to surround her.

The "Ignite" effect was burning her health, the effect of the gill grass was almost completely gone, and a feeling of suffocation was coming over her like a tide.

The blue bar has completely run out of ammo and supplies.

Despair! Utter despair!

"Retreat!" That was the only thought in Lux's mind.

She focused her attention as much as possible, forcibly suppressing the feeling of suffocation, and pointed her wand sharply behind her, silently chanting, "Yugadilemevisa!"

An upward buoyancy instantly acted on her, and at the same time, she desperately kicked her legs, using the buoyancy and her last bit of strength to swim wildly like a torpedo being launched, without looking back, in the direction she remembered coming from.

She could only rely on the Water and Fire Invulnerability Spell to block out most of the water pressure and cold, as well as the weak buoyancy from the Levitation Spell, to desperately kick her legs and struggle toward the increasingly bright water surface above, which symbolized air and freedom.

The mermaid guards' angry roars and the sound of the bone fork breaking through the water seemed to be right behind her; Lux could even feel the force of the water being stirred up.

Lux didn't dare look back, channeling all her remaining magic into kicking her legs, her mind focused on only one thought: Get up! Get up!

"Puhaha—!!!"

Finally, her head burst through the water.

Upon hearing the noise, Lumi immediately grabbed a passing field mouse and rammed it hard into it.

"Cough cough cough... Ugh..." Lux teleported to the lawn, half-kneeling and coughing violently, spitting out a mouthful of lake water with a rusty taste. She was soaked, her long golden hair sticking messily to her pale face, like a stranded, dying fish.

"Hey sis, what happened down there?" Lumi asked anxiously, circling around Lux.

"Lumi..." Lux's voice was terribly hoarse, carrying the weariness of surviving a disaster, but her eyes were unusually bright.

"We found... the unsealed scroll... that thing... allows people to use Summoner Spells..."

She paused, recalling the Mermaid Guardian's teleportation into the wall and the terrifying ignition at the Mermaid Queen's fingertips, still feeling lingering fear.

This ignition actually burned half of her health; these runes are clearly adjusted by reality.

Lux gritted her teeth, propped herself up to sit, and clung to her body with the school robe she had left on the shore. "Next time, with just the gill sac grass and these skills, going down there would be suicide."

She looked at her slightly trembling hands, the frustration of being unable to use her strength and having her spells greatly diminished underwater was still fresh in her memory.

"I must learn Silent Spells!" Lux said decisively. "At least I need to be able to silently cast a few key spells underwater, then level up to six and unleash a massive electric cannon on them!"

After cleaning herself up, Lux quietly returned to her dorm room.