Hogwarts: The Savior's Strong Cousin

Back at Gryffindor Tower, Harry found Hermione and Ron in the common room, who were already waiting for him to come back. Seeing Harry's tired look, Hermione asked with concern, "Harry, are you okay? Have you found any clues?"

Harry nodded and told them what he and Professor McGonagall had found in the library. Hermione listened very carefully and nodded in agreement from time to time, while Ron looked a little worried: "Cyrus Knox sounds really dangerous. We must be very careful."

Harry smiled and comforted Ron: "Yes, we need to be careful, but we can't be afraid. We have faced many difficulties together, and this time will be no exception."

Hermione's eyes sparkled with wisdom: "We can start from now on and make a detailed plan. First, we need more powerful defensive spells, and then study Cyrus's weaknesses."

Although Ron was nervous, he nodded firmly: "Yes, we will find a way."

Over the next few days, Harry and his friends spent many hours in the library, studying various defensive spells and charms. They tried to find the most effective defense, while also trying to decipher the traces of Cyrus Knox's magic.

One night, Harry found an ancient book in the corner of the library, which described in detail a powerful defensive spell called "Light Barrier". This spell can not only resist dark magic, but also reflect some magical attacks.

"Hermione, Ron, come and see!" Harry called to them excitedly, "I found a powerful defensive spell called 'Light Barrier'."

Hermione came over quickly and read the contents of the book carefully: "This is indeed a very powerful spell, but it requires extremely high magical control and concentration."

Ron looked at Harry with some concern: "Can you do this, Harry?"

Harry nodded firmly, "I will practice hard. We must do everything we can to protect Hogwarts."

In the following days, Harry continued to practice the "Light Barrier" spell with the help of Hermione and Ron. They trained in a secret practice area, trying to improve the effect and stability of the spell. Every time he failed, Harry would try harder, with a sense of responsibility and protection for Hogwarts in his heart.

During a practice session, Harry finally succeeded in casting a complete "Light Barrier". A dazzling light burst out from the tip of his wand, forming a solid protective barrier. Hermione and Ron looked at the light with relief and hope in their eyes.

"Harry, you did it!" Hermione said excitedly.

Ron also patted Harry on the shoulder: "That's great, Harry."

Harry smiled and nodded, but he knew that this was only the first step for them to face Cyrus Knox. Next, they needed to find more clues and uncover the secrets hidden in the darkness.

In the days that followed, Harry and his friends continued to search for clues in the library and the bookcases. They found some ancient records that mentioned that Cyrus Knox had studied the Dark Arts in a secret room in Hogwarts. This room was located deep in the dungeons and only a few people knew about its existence.

One night, Harry, Hermione and Ron decided to go to the dungeon to find the secret room. The air in the dungeon was cold and damp, and there was a gloomy atmosphere all around. They walked carefully in the narrow corridor, their hearts full of tension and expectation.

"We need to find that room quickly," Hermione whispered, "The atmosphere here makes me feel a little uneasy."

Harry nodded and tightened his grip on his wand: "Yes, we must be careful."

Ron kept looking around and said vigilantly: "I always feel like there is something watching us here."

Suddenly, they found an ancient stone door in a hidden corner. There were complex runes engraved on the door, which seemed to be guarding some secrets.

"This must be what we're looking for," said Harry, "but we've got to find a way to open this door."

Hermione studied the runes carefully for a while, and finally found the spell to open the stone door: "Opening spell - 'Alohomora'."

As the spell was chanted, the stone door slowly opened, revealing a dark room. There were many ancient books and magic tools in the room, and the air was filled with a strong smell of black magic.

Harry walked into the room, nervous and curious. "There must be Cyrus Knox's research records here."

They began to search the room and soon found a thick manuscript, which detailed Cyrus Knox's research on the dark arts and his conspiracy against Hogwarts.

"We've found it," Hermione said excitedly, "Here lies Cyrus's plan and his weakness."

Harry flipped through the manuscript, hope rising in his heart: "We must bring this information back as soon as possible and find a way to stop Cyrus."

Ron looked outside the room nervously: "We have to hurry, I feel very uncomfortable here."

After returning to Gryffindor Tower, Harry, Hermione and Ron continued to study the manuscripts brought back from the dungeons. The contents recorded in the manuscripts became more and more profound, and Harry felt an unprecedented tension. Every page seemed to hide new dangers and unknown threats.

Late one night, Harry was studying a spell analysis about Cyrus Knox in his dormitory when he heard a slight sound of footsteps outside the door. He looked up and saw his roommate Dean Thomas standing at the door with a strange light in his eyes.

"Harry," Dean whispered, "what are you looking at?"

Harry closed the book warily. "Just some research on defensive spells. What's up?"

Dean smiled, but it made Harry uneasy. "I heard you've been working on some very interesting stuff lately. Do you mind letting me see it?"

Harry's heart tightened, realizing that Dean might be controlled by some kind of dark magic. He stood up and tried to change the subject: "Dean, these things are complicated and may not be suitable for you."

But Dean suddenly became tough, snatched the book from Harry's hand, and a crazy light flashed in his eyes: "Let me see!"

Harry tried to take the book back, but Dean seemed to be driven by some powerful force, so powerful that Harry felt powerless and could only watch Dean take the manuscript away.

"What are you doing!" Harry shouted angrily. "Give me back my book!"

Dean smiled coldly: "You don't understand, these books have infinite power, they don't belong to you."