Imperio, a spell that grants total control over another's mind.
With this spell in effect, Rey could lift the Leg-Locker and Silencing Charms. The one-legged Black Prison Wizard, now under the influence of the Unforgivable Curse, would obey Rey's every command. Even if Rey ordered him to die, he would execute the order without hesitation.
There is a fundamental difference between living beings and inanimate objects.
The barrier at the cave entrance was clearly designed to target living beings other than Black Prison Wizards—or living beings not in direct contact with them.
In other words, the Black Prison Wizard acted as a "key." Anything he carried or touched could pass through the barrier safely.
Magical wards and barriers came in infinite varieties. Some granted invisibility, some were purely defensive against physical attacks, and others acted as long-range sensors.
However, most barriers operated on a simple, singular rule set. They were like basic computer programs capable of fixed discrimination; they weren't artificial intelligences capable of complex logical judgment.
Since the Black Prison Wizard could enter and exit freely, this barrier wasn't like the comprehensive "keep everything out" shield over Hogwarts in the movies.
This was a loophole. A loophole Rey intended to exploit. But for safety's sake, he needed to test it one more time.
Rey's idea was simple: Transfigure an animal into an object, place it on the Black Prison Wizard, and have him walk through the barrier.
The experiment had to use a living animal Transfigured into an object. Magic was full of unknowns, and Rey dared not risk himself lightly. He had to simulate the intended process as closely as possible.
His strategy was clear: Transfigure himself into an object and have the Black Prison Wizard carry him inside.
---
If Horace Slughorn could turn himself into an armchair, Rey could certainly turn himself into an object.
For some reason, Rey had a high aptitude for Transfiguration. A critical factor might be his partial dragon identity. Dragon blood coursed through his veins, and in the Twelve Uses of Dragon's Blood, it was noted that higher-grade dragon blood significantly boosted Transfiguration magic.
For a true dragon, Transfiguration was likely just a simple skill that consumed magical energy. If not, the Black Dragon wouldn't have been able to assume the form of Madam Hooch so naturally.
The Black Prison Wizard walked back and forth through the barrier twice, carrying either a live animal or a stone that had been Transfigured from an animal.
Everything appeared normal. Neither the animal nor the stone was blocked or dissolved into bone. It seemed the barrier's logic was indeed tied to the Black Prison Wizard as a medium.
When Rey lifted the Transfiguration spell, the field mouse scampered off the wizard's shoulder in a panic.
Although it was confirmed that the Black Prison Wizard could carry living beings (or objects made from them) through the barrier, wizards were different from ordinary animals—they possessed magic.
Rey wasn't 100% certain about this variable.
"You stay here and provide support. I'm going in."
The situation inside the cave was unknown, and Rey didn't want Helena to take the risk.
"I'm going with you!"
However, as Rey prepared to cast the Transfiguration spell on himself, Helena grabbed his arm. Her tone was absolute, leaving no room for argument.
No matter what happens, we won't be separated. Her eyes seemed to remind him of his own promise.
Facing her determined gaze, Rey sighed in defeat.
Helena was a strong-willed woman. Once she made up her mind, almost no one could change it—not even Rey. If he forced her to stay behind, he could only imagine the explosion that would follow.
So, he compromised.
Transfiguration was Rey's specialty. Although Helena wasn't an expert in self-transfiguration, Rey could turn her into a rabbit.
Two rabbits. Two people.
The one-legged Black Prison Wizard picked them up and walked toward the cave.
One step. As they passed through the barrier, Rey felt a cold sensation wash over him. The energy of the ward clung to his body, making him feel as if he were being scanned inside and out.
It was uncomfortable, but safe. They weren't blocked, and neither he nor Helena—currently in rabbit form—was dissolved into a skeleton.
---
Passing through safely was expected.
As soon as they cleared the barrier, a downward-sloping tunnel appeared before them.
Rey immediately reverted to human form and lifted the Transfiguration on Helena. Unlike an Animagus, being Transfigured into an animal left them defenseless, so returning to their human bodies was the priority.
However, the moment Rey passed through the barrier, Cardinal Alofman, sitting beneath his canopy on the highest peak near Hogwarts, suddenly stiffened.
A sensory signal had just triggered in his mind.
He sensed a person. A person he was all too familiar with—the infant he had asked the Pope to bless.
"That baby... is awake! But why has he appeared at the summoning grounds for the elves...?"
The location of the summoning circle was critical, and Alofman had personally set up the wards there. Therefore, certain specific magical signatures detected by the ward were transmitted directly to his mind.
Confusion. Disbelief.
But mostly, overwhelming excitement. Although he couldn't be certain the signal was truly the infant Ryan Evans had brought back, the sensation was too similar to ignore. Regardless of the truth, he had to go back and check.
If this feeling was real, his schedule for the total blood transfusion could be moved up immediately.
"Divert one-third of the elves to return and surround the summoning grounds. Set up a containment ward to prevent anyone inside from escaping."
Alofman, who had been silent for a while, suddenly issued the order. The Black Prison Wizard acting as his messenger paused, stunned.
Hogwarts was the primary target. Why would the Bishop suddenly order a third of their forces to retreat and surround the summoning site?
While the summoning grounds were important, breaching Hogwarts was paramount. Besides, they already had enough elves; even if the summoning circle was destroyed, it wouldn't impact the overall war effort significantly.
"Why are you still standing there? Go!"
Seeing the messenger hesitate, Alofman let out a cold snort that made the wizard tremble in fear.
The messenger scrambled to relay the order. Alofman stood up, gazing at the flickering wards of Hogwarts in the dark night, feeling conflicted.
The protective barrier over Hogwarts was already thinning. Diverting a third of the elves would undoubtedly prolong the time needed to breach it.
He hesitated on whether he should go back personally to verify the signal or wait until Hogwarts fell.
The Pope's orders were absolute. Alofman dared not feign compliance, no matter how much favor he curried.
"I'll go back after we breach Hogwarts. With the summoning grounds surrounded, whoever it is won't be able to escape."
After a moment of contemplation, Alofman made his decision. He immediately ordered his Black Prison Wizards to accelerate the erosion of Hogwarts' defenses.
---
There was only one summoning site, yet thousands of elves were being sent to surround it. The Black Prison Wizards were confused, but they faithfully executed Alofman's command.
As the order went out, a distinct shift occurred on the battlefield. A massive section of the elf army surrounding Hogwarts began to peel away and head back toward the summoning grounds.
The distance wasn't far, and magic-wielding elves moved quickly. They soon arrived at the sparse forest where Rey was. Due to their sheer numbers, they merged with the remaining siege lines, creating a continuous sea of creatures.
Using the massive rock formation as a center point, the elves surrounded the area so tightly that not even water could leak through. Additionally, several teams of Black Prison Wizards set up a large-scale containment ward on the perimeter, trapping the mass of elves—and anyone inside the cave—within a magical cage.