In LOTR with Harry Potter Sign-In System!

Facing the approaching ghost army, Kael took out Eärendil's Light and infused it with magical power, releasing brilliant holy radiance.

The dazzling light made the ghosts instinctively uncomfortable, and they all stopped.

Though Eärendil's Light couldn't cause fatal damage like it could to evil spirits and demons, ghosts were still fundamentally aligned with darkness and would instinctively retreat when faced with such holy light.

Kael held aloft the crystal vial, releasing its radiance, and called out once more to the Ghost King.

"King of the Mountains, I have no intention of being your enemy. Please stop attacking. Though I cannot help break your curse, I know someone who can help you find release!"

Hearing this, the ghosts' attack paused.

The Ghost King stared at Kael with those dead, hollow eyes, asking with suspicion. "You're not lying?"

"I swear by my name as a wizard that my words are true!" Kael said with sincere certainty.

"Who is it? Who can help us break free from the oath's bonds?"

"He who tied the bell must untie it. Though you swore loyalty to Isildur years ago, and though Isildur is no longer here, you can still serve his heir, thus fulfilling your oath and gaining release and rest," Kael explained.

But before he could finish, the Ghost King suddenly flew into a rage, erupting with a terrifying aura. The sea of skulls around them ignited with ghastly green flames, radiating bone-chilling cold.

"You're lying to me! Gondor has no king. Isildur's bloodline has ended! No one can break the oath upon us!"

"Wizard, you dare toy with the King of the Dead! Your bones will remain here forever, rotting alongside us!"

The surrounding ghosts also became more hideous and terrifying in the ghostly flames, like demons from hell come to claim souls.

Clearly the ghosts were thoroughly enraged, unleashing their most powerful forces.

Kael was startled by this sudden turn. The blazing ghost fire gave him a sense of heart palpitations, as if it could harm his very soul.

"Wait! I'm not lying. I can swear to you that Isildur's bloodline has not ended!" Kael shouted hastily, surrounding himself firmly with his Patronus to prevent the ghost fire from burning him.

"You say Isildur's bloodline still exists in the world? Are you telling the truth?" The Ghost King remained full of doubt.

Kael nodded quickly.

"Though Isildur's bloodline in southern Gondor has ended, there remains a direct descendant in the north."

The Ghost King's fury subsided slightly upon hearing this, but he remained skeptical. "But how can I believe what you say is true?"

"This matter would be hard to fake. Every generation of Isildur's northern heirs is sent to Rivendell to be raised by elves, and this generation's heir is currently growing up. He will be the rightful heir to both northern Arnor and southern Gondor. Even the broken sword Narsil will be reforged in his hands. His future is destined to be extraordinary. He will surely face great conflicts, and then you can serve him to fulfill your ancient oath."

Kael explained while guaranteeing. "When the time is right, I can guide him here to help you achieve complete release."

The Ghost King's fury gradually subsided, his aura weakened, and the soul-freezing ghostly flames around them instantly disappeared.

"I need a guarantee, wizard."

Seeing this, Kael secretly breathed a sigh of relief and nodded. "I can make a magical vow with you, an Unbreakable Vow. How about that?"

But the Ghost King clearly wasn't willing, shaking his head.

"You're a wizard. Magic is your specialty. Magical oaths may not be able to bind you."

"Then what do you want?" Kael frowned.

"I want you to swear before the Stone of Erech to help us find release, or you will suffer the same doom as us!"

"Very well, I agree."

Even without him, Aragorn would help them find release in the future anyway. He could guide Aragorn when the time came and fulfill the oath.

Just then, the system responded.

[Hogwarts Check-in System: Located at White Mountains - Paths of the Dead, check in?]

"Check in."

[Check-in successful. Congratulations on obtaining the Resurrection Stone, one of the Deathly Hallows, creation method!]

The Resurrection Stone? Kael was surprised.

He hadn't expected to gain this from the check-in.

But he remembered this thing could only summon beings more real than ghosts but more illusory than physical bodies. It couldn't truly resurrect the dead.

It was quite useless, hardly deserving the name "Resurrection Stone."

However, Kael was currently dealing with the ghosts and couldn't spare attention to deeply understand the newly acquired knowledge, so he temporarily set it aside.

Under the ghosts' guidance, Kael continued deeper into the cave. After walking for a long time, he finally emerged from the mountain cave onto the southern side of the White Mountains.

This cave exit was near the Stone of Erech.

Surrounded and escorted by the ghost army, Kael followed the Ghost King to the top of Mount Erech.

There were no trees around here, only a spherical black boulder.

The black stone was about 12 feet in diameter or larger, with its lower half buried in the ground atop Mount Erech. The upper half exposed above ground was taller than a person.

The black stone was incredibly heavy. Since being placed here, it had never moved and was always regarded as a symbol of oaths.

Kael looked at this boulder curiously and tried using spells to lift it.

Even using all his strength and maximum magical power, the boulder remained completely unmoved, as if rooted in the ground.

No method could budge it.

Kael was very curious about how the Númenóreans had managed to transport such a heavy boulder across the ocean to this place.

Unwilling to give up, Kael used his Flammifer and divine spear Aeglos to strike and stab the boulder.

But to his surprise, neither weapon left any mark on the black stone.

He had never seen such hard material. What was this black stone made of?

Seeing he couldn't do anything to the black stone, Kael gave up further attempts. Under the witness of the Ghost King and all the ghosts, he swore before the black stone to help the ghosts find release.

The moment the oath was made, Kael keenly detected an invisible force emanating from the black stone.

His oath was then captured by the black stone and imprinted within it, becoming part of the stone.

At the same time, he sensitively felt the black stone seemed to become slightly heavier.

This feeling was very subtle. If Kael hadn't possessed goblin sensitivity to magic, he might have dismissed it as an illusion.

Kael finally understood why this black stone was so heavy.

Clearly the black stone absorbed oaths and became heavier. Over thousands of years, it had absorbed countless oaths. Its weight probably exceeded that of Mount Erech beneath it!

How could Kael's magical power lift the weight of a mountain?

[Hogwarts Check-in System: Located at Stone of Erech, check in?]

Kael was stunned, then surprised.

He hadn't expected another check-in opportunity here!

"Check in."

[Check-in successful. Congratulations on obtaining the Marauder's Map creation method!]

Well, better than nothing. Kael wasn't too disappointed. Having something was better than nothing.

Due to making the oath, the Ghost King's attitude toward Kael softened.

Kael once again returned with the ghosts to the Paths of the Dead, the atmosphere no longer hostile.

"Wizard, since you've made the oath, you're our guest. What do you need? Whatever exists in these mountains, we'll help you find," the Ghost King said.

Kael didn't stand on ceremony and stated his purpose. "I'm seeking something called Sulfur of the Soul. It resembles sulfur and appears where souls gather. Do you have any memory of it?"

"Sulfur of the Soul?" The Ghost King looked puzzled, clearly hearing of this for the first time.

He then asked other ghosts. "Have any of you seen such a thing?"

Most ghosts shook their heads, indicating they had no memory.

One lone female spirit spoke hesitantly, "I seem to remember seeing some yellowish ore in a distant tunnel, though it was stained with our tears. I cannot say for sure if it was the Sulfur of the Soul you seek."

Kael's eyes lit up upon hearing this. "Where? Can you lead me there?"

Kael then followed the ghost's guidance toward a tunnel leading deeper underground.

They reached the tunnel's end, a tall black stone wall the ghosts called the "Wall of Memory" or "Wall of Sighs." It was said that before this wall, the ghosts' thoughts became clearer, and they constantly reminisced about memories of being alive, regretting and grieving their fate of breaking oaths and finding no rest.

Upon arriving, Kael first saw the black stone wall.

He curiously reached out to touch it. It felt metallic and transmitted a cold, stinging sensation, like touching ice.

This black stone wall was made of unknown material and radiated an eerie aura.

Though somewhat curious about the wall, Kael turned his attention to the surroundings.

This looked like a mine, with black ore embedded in the surrounding stone walls. On these black ores were scattered yellow marks that had penetrated deep inside, like impurities.

According to the ghosts, these yellow marks were formed from thousands of years of ghostly tears.

Kael was delighted. He had finally found Sulfur of the Soul.

With the ghosts' permission, Kael directly excavated all the ore containing Sulfur of the Soul and stored it in a space bag.

He planned to take it back for remelting and purification to extract the Sulfur of the Soul.

After half a day's work, Kael had completely stripped the mine of all ore containing Sulfur of the Soul, considerably widening the mine's space.

He then looked at the black stone wall that could clarify ghostly thoughts. After consulting the Ghost King, he used the divine spear Aeglos to cut away part of the black wall for research.

Kael made a solemn agreement with the Ghost King: once Isildur's heir, Aragorn, came of age, Kael would guide him to the Paths of the Dead to finally break their thousands-year curse.

Aragorn was now only in his teens, but for ghosts who had waited thousands of years, waiting a few more decades was no problem at all.