Remus walked slowly up to Dumbledore's office. He had something very important to tell him. Something that could help them catch Sirius Black. His best friend. No. His former best friend. He didn't deserve that, or any other title, after what he had done. Not after his worst betrayal yet. And he was going to give Dumbledore the information that could possibly help him find Sirius Black sooner. It was his former best friend's biggest secret.

He was going to tell Dumbledore that his three best friends had become Animagi at the age of fifteen. That they had been accompanying a known werewolf during the full moons in their Animagus forms. It was going to be admitting that he had abused Dumbledore's trust, that he had used that trust to make his transformations easier that would be hard. Remus didn't know how Dumbledore would react to that, but it was more important that Sirius be caught. Remus wanted Sirius to be caught. He wanted to see what had become of the friend he once knew, what had possessed Sirius to go to the Dark side and betray those he had called his brothers. It would be worth giving up the Marauders' greatest secret.

"Sugar quill," he said as he approached the entrance to the Headmaster's office. The eagle jumped aside, and Remus walked onto the stairs that moved steadily upward.

He knocked on the door. "Enter," a quiet voice said from inside. Remus walked in.

"Ah, Remus," Dumbledore said warmly. "To what do I owe this pleasure?"

Remus sat down on one of the large, plump chairs in the room. "I have some information that I think will help you catch Sirius Black."

Dumbledore's smile faded. His look turned serious. He nodded at Remus. "Go on then, Remus."

Remus took a big breath, then started on his story. He told Dumbledore how James and Sirius had figured out what he was in the beginning of second year. They had accepted him for what he was, and wanted to help make his transformations easier for him. They, along with Peter, had gone into the library and read all about werewolves and had figured out that a werewolf's bite is only poisonous to humans. Animals weren't affected. So they started researching Animagi and how to become one. By fifth year, they had managed it. They immediately started following Remus into the Shrieking Shack and accompanying him while he was in wolf form. And it had helped. He had been less inclined to hurt himself while they were there. They had never registered, as far as he knew, and so Sirius could still be wandering around in his Animagus form and nobody would know it was him.

Remus swallowed. "I'm sorry for not telling you this sooner," he apologized. "I'm so sorry for not telling you at all, or for not allowing them to do that. I apologize profusely for abusing your trust." He hung his head, awaiting Dumbledore's verdict.

"I accept your apology," he said at last, "although none was needed." Remus looked up at him in surprise. A small smile was on the old man's face. "I understand why you wanted this, and I forgive you for waiting so long to tell me. Now, the climax of the story, what were the Animagus forms? All three of them, if you please."

Remus nodded. "James was a stag, Peter was a rat, and Sirius is a large, black dog. He looks like the Grim, if helps. He doesn't really have any distinguishing features, except that his eyes are the same, but that'll be hard to identify unless he's still and you're right up close."

Dumbledore nodded. "I appreciate your telling me this, and I reassure you that it will most certainly help in the search for Sirius. He will most likely be caught before this school year ends."

Remus let out a sigh. He didn't want to admit it, but he had been frightened that Sirius would try to kill him, once he killed Harry. He was the last one of the Marauders left. The last one who could tell anybody his secret. The last one he needed to kill. But he shouldn't have worried. With Dumbledore as Headmaster, nobody would have to be killed.