Harry's suggestion takes into consideration but only for a couple of seconds as they went to the Library where they are going to search for that.
He is surprised as Susan and Tracey who normally like to have fun while studying is so focused on finding it.
When they are on their way there they saw Luna who is the front of the Dementor. Her face is completely paled out when its face comes close to her.
Harry took out his wand and use Patronus's charm as soon as possible to counter Dementor so that they get away from her otherwise her soul is going to be sucked out by it.
When Harry used the charm a winged horse materialized which he learn is Thestral who not only knocked the Dementor but destroyed it. Harry used the spell and learn that it can't kill them just make them run away from there. He doesn't know how it happens and how his Patronus change from stag to Thestral but suddenly he remembers Lady Death and now he knows this is what she meant by changing some things.
They all run towards Luna to check that everything is good, they check that she is alive but unconscious.
"We should take her to Madam Pomfrey first."
Harry carry her and started walking toward the infirmary.
When Pomfrey saw them there she is shocked to see her again just in a very short period. She tells him to put Luna on the bed.
"What happens to her Mr. Potter."
"She had almost her soul sucked out by the Dementor but we arrive there on time and Harry uses Patronus charm to drive it away."
Madam Pomfrey is shocked and frightened when she hears that this young girl has her soul sucked by the dementor. She instantly started the analysis and was relieved that nothing happen and she was unconscious just because of physical and mental exhaustion.
She then speaks to others so that they can be relaxed as they are stressed about her condition.
"She is fine just take some time to recover her energy."
Everyone sighed in relief after hearing that she is okay and just exhausted.
Harry has broken his temper when he thinks about what could happen if they are late or they never come there. He is feeling guilty as all the things never happen if he removes them before the start of the year due to his control over Hogwarts.
After seeing what happens to his new friend, he decided that it is not good to stay quiet and make others suffer to achieve something. If he did that then there is nothing difference between him and Dumbledore.
"I think I had enough of them."
They all turned toward him when he said that and they know that he is going to fight back and not watch from the sidelines.
"Are you sure Harry?"
"Yes Hermione, I am sure about it. If I didn't take action I don't know about what can happen and how many are going to suffer."
After saying that Harry lashes out of the room and starts walking toward the Headmaster's office. When he comes in front of the door, the Gargoyle who is guarding the pathway stops him. But when Harry releases his power he let him go as the castle permits him to do so.
When Harry entered the room Dumbledore is completely shocked as he didn't get notified about it and he can't enter inside if he doesn't know the password there are only a selected few who know it and Harry is not one of them.
"Harry, it is a surprise to see you here. Do you have something to say to me?"
Harry ignored Dumbledore speaking his name as it is not the main issue.
"I want you to throw dementor out of the Hogwarts. There is a student who got attacked and if we have not come there in time she is going to get her soul sucked by them."
"I am sad hearing that the student was attacked by the dementor but I am unable to do anything about this as the ministry placed them here to catch Peter Pettigrew."
"You are the Headmaster of Hogwarts and Chief Warlock, you should prioritize the safety of your students."
"I know but it is the order by the Minister of Magic. I tried to talk to him that it is not a good idea but he didn't listen to me."
"If you can't do anything about it then I have to do it myself."
Harry speaks angrily about the comments of the Headmaster and his reaction to the attack.