The beginning of fourth year Severus gave them their own Time-turner, and finally told them that he got them in Germany at a wizarding black market. Severus provided Harry with Polyjuice potion in exchange for the truth behind his missing Potion Ingredients in 2nd year, and used the floo along with some random wizards hair he got off someone in Diagon to bring Pettigrew stunned (as the rat had been for the last two weeks) into the Auror Department and dropped the animagus off with an Auror he made sure he didn’t recognize. The Auror looked at him as if he was blimey until he read the note attached to the small cage "Peter Pettigrew, unregistered Rat animagus, Death Eater, Serial Killer, Secret Keeper and Traitor to James and Lillian Potter’