The Defense Against the Dark Arts professor's office.

The room was gray and not very bright. Remus Lupin sat quietly on the sofa. The wolfsbane potion continued to suppress his body, like some kind of terrible spiritual creature, draining his physical strength bit by bit.

The full moon had not yet arrived, but he was already exhausted.

"Gurgle~"

The kettle in the corner boiled, leaping and spewing out large streams of steam. Lupin dragged his body up. Before and after the full moon, he tried not to use magic. After two minutes, he made himself a pot of tea.

Throwing the tea bag into the trash can, white steam floated above the cup. Lupin's eyes sparkled in the dimness.

"Sirius..."

He has always been an introverted person and rarely showed his true emotions. But under the dual fatigue of body and mind, his mood inevitably fell into a continuous depression. He found himself thinking of this person again.

The photo on the wanted poster did not show his original appearance at all. Lupin always subconsciously brought the young Sirius into it, which made his feelings more complicated and sad.

"Should I tell Dumbledore about Sirius's Animagus?"

This question has been bothering him for a long time, but he couldn't muster up the courage to admit to Dumbledore: he had betrayed his trust when he was a student. Not only did he leave the Shrieking Shack, but he also followed three people around...

Dumbledore's trust was extremely important to him. When he was a child, it was Dumbledore who walked into his house and persuaded his father and mother to accept his admission. In the first one or two years, Dumbledore or Madam Pomfrey accompanied him to transform. Later, as he grew up, he persuaded Dumbledore to allow him to complete the full moon transformation independently.

The chain of the Shrieking Shack was very strong, which was one of the reasons he mentioned.

Dumbledore agreed to a limited extent. He set a rule that Madam Pomfrey would take him to transform, but would not always watch him, and occasionally let him go to the Shrieking Shack alone.

He carefully maintained the secret, even though he was discovered by two sharp guys as early as the second year, and the number of people who knew he was a werewolf also expanded to six: Dumbledore, Madam Pomfrey, Professor McGonagall, James, Peter and Sirius.

Once James suddenly had the idea to learn Animagus, because werewolves were only dangerous to humans, James thought he could turn into an animal to accompany him. This idea was immediately responded to by Sirius, and for a while, their enthusiasm remained high.

He didn't care too much at the time, but was "happy" to provide some numbers, telling them how profound Animagus was, how many wizards had failed one after another in a century, and the names of the last successful ones could not even fill two lines on the paper.

"I love your dry humor, Lupin." James said to him at the time.

Things changed in the fifth year. On the first full moon after the holiday, he locked himself in the Shrieking Shack as usual - he was already very skilled at it, but when the full moon passed and he gradually recovered, he opened his eyes and saw two huge animals:

a big black dog and a stag. In his astonishment, they turned into two familiar companions, James and Sirius. They grinned at him, "We kept it a secret for a whole summer vacation just to see your surprised expression."

It was hard to describe his mood at the time, happy and sad - in order to cross the Whomping Willow, they hurt themselves all over - and even complained a little, what if he hurt them? But looking at their smiles, he compromised again.

Two months later, with the help of James and Sirius, Peter finally succeeded. With their company, his mood in the werewolf state was much calmer, not always irrational, which might be because James and Sirius's Animagus could suppress the werewolf, and no one stimulated him to go crazy.

They began their adventure. A werewolf and several animals running around in the dark night! Looking back now, Lupin still felt puzzled by his youth and ignorance, but at that time they treated this matter as a joke and were proud of it...

He couldn't help feeling guilty - he broke the safety rules set by Headmaster Dumbledore with his own hands. Although he felt uneasy for a long time, he did not refuse to participate in the formulation of the next adventure.

In the office, the tea had already cooled down.

Lupin deceived himself and thought: At the right time, I will tell Dumbledore everything, including my hypocrisy and cowardice. He said to himself, and then thought with self-loathing, come on, you should have told Dumbledore a long time ago, when Sirius tried to break into the castle.

But he subconsciously postponed this decision again and again, and like an ostrich, naively believed that Sirius had been frustrated and he would never appear again.

"Maybe he learned the evil black magic from Voldemort... But Hogwarts has Dumbledore, he won't succeed."

Lupin showed a self-loathing expression, he picked up the cup and poured the cold tea into his stomach.

He thought of Neville and Harry. He subconsciously paid attention to them. He had more pity for Neville. His parents were once his comrades-in-arms. Although they didn't interact much, the Longbottoms were very friendly people.

He saw Neville's timid character at a glance. He hoped that Neville could overcome his fear, but Snape's counterattack seemed to make the child endure more scolding. He didn't know if his several comforts had any effect.

As for Harry, he was more like his own son or nephew... although he concealed this feeling very well.

By the way, he still had to teach Harry the Patronus Charm. Lupin cheered up. He should find a Boggart. He knew this creature very well. This came from the bedtime stories he heard when he was a child. His father was an "authority on non-human supernatural phenomena" and knew everything about poltergeists, Boggarts and other ghosts.

Even the bond between his father and mother was because of a wild Boggart...

Lupin suddenly thought that Harry would definitely ask about his parents. At that time, how much should he reveal? And Sirius, it seemed that the more he said, the more wrong he would be.

"Knock knock."

A low knock on the door interrupted Lupin's thoughts. He pushed open the door and saw Dumbledore standing outside.

"Dumbledore - why are you here?" Lupin asked in surprise.

Dumbledore said in a deep voice: "Bad news, Sirius Black took advantage of the opportunity when Harry and his friends visited Hagrid to attack them."

"What!" Lupin's eyes widened, his head dizzy, "Harry - are they okay?"

"Almost, he almost succeeded, Remus." Dumbledore said. "Harry's best friend is lying in the hospital now. No one can guarantee when the next attack will happen."

Lupin held onto the door frame, seemingly having lost all his strength. After a long moment, he said dejectedly, "I will tell you everything I know, Professor Dumbledore, including Black's secrets and my deception of you... I only hope that you can listen to the story in its entirety and not leave in anger halfway through."

"This is exactly why I came to you, Remus," Dumbledore said calmly.