When Harry and Remus come out of the floo, Dumbledore told them to sit in the chair in front of him and they sat down. The only reason he decided to stay there instead of dismissing him, was to know what Dumbledore is planning. They both know that he is going to start by asking them about today's business and they were right but what they want is his next question.
"Mr. Potter-Hogwarts, can you tell me about your today's business."
"As I told you before, you are not allowed to ask me that question as you are not related to me outside the school."
Dumbledore then looks into his eyes for a few minutes before asking him another question.
At that time Dumbledore is conflicted about using Legimency on him, but he decided that it is not good to use it on him. If he gets caught, he is going to be in trouble as Harry holds more power than him within the school and he doesn't want to lose the position of headmaster as it will be bad for his plan for the greater good. So, he decided just to ask him questions and hope to get the answer he want.
"Then can you tell me how can you use the floo without my permission which I don't remember giving you?"
"Headmaster, I never thought that you are that forgetful."
"What do you mean about that?"
He asked with his face and his voice looked like it lost its grandfatherly tone.
"You forget that I am Heir Hogwarts and can use anything in the castle without your permission and it also included the floo."
Dumbledore then asks him another question which is what Harry wants to hear. A question through which he can find out what Dumbledore is up to. As he noticed that Dumbledore is not as focused on him as much as he is before. Sometimes he does not show up at Great Hall for dinner or lunch through which Harry assumes that he is searching for something or someone
"Do you happen to know about Heir Pendragon?"
At first, Dumbledore doesn't want to ask this question and tries to find out about him on his own but it didn't go as he wants. He was not able to find anything not even a new clue about his existence. The only clue he has about the person is the letter that is sent to the ministry for the trial of Sirius Black.
After that letter, there is no news about that person. He wants to know where he disappeared. The most influential person in the whole wizarding politics just disappeared after sending them his first and last letter which gives them knowledge about his existence.
At first, he thinks that the letter is forged as how can there be Heir Pendragon as the whole Royal family is gone many centuries ago but when he focuses his attention on the seal he knows that it is real. He read in the old book that the royal family has a very unique seal that cannot be forged as it is protected with magic.
"No, I don't know about him. I heard the first time about Heir Pendragon, is he someone I know."
Harry asked innocently but inside he is controlling his laugh.
"He is the person who makes Sirius's trial possible."
"I don't know him but if you know him, please tell him that I say 'Thank you for the help'."
"I will."
Dumbledore said but before it can progress anywhere, Remus stand from his position and speak.
"Professor, Mr. Potter is pretty tired so I think it is best to postpone the questions for now."
Remus said this and he drag Harry out of the Headmaster's room before Dumbledore even answer.
When they are outside of the room and somewhat far away from the office, Remus looked toward Harry, and then both started to laugh like maniacs. Both of them are laughing as they know what Dumbledore is not, he is just asking Harry about himself and the way Harry lies to him with that innocent face.
They laugh for solid five minutes before stopping which only happens because their stomach is starting to hurt a little because of all the laughing.
"I think it is all for today."
"Yes, it is all for today and you better go to your and rest as today is quite a tiring day."
"Not tiring but adventurous."
"But adventure makes the body tired so you have to rest and also don't forget that you have to tell the girls about today. But as it is already quite late so you should tell them tomorrow."