Brian saw the boy. Well, sort of a boy. He was rather stuck, mid animagus transformation. He was part dog and part boy. He felt sorry for him, but it wasn't like they hadn't run into that in St. Mungos before.
"Got yourself stuck, have you?" Brian said gently. "I can fix that." He flicked his wand and undid the accidental magic that had the boy stuck between dog and boy. In a moment, there was, before him, a sandy haired young boy. He reminded Brian of how he had looked when he had first gone to live with Robert. He drew a cookie from his pocket and handed it to the boy who tried to shove nearly all of it in his mouth at once. "Slow down. I have more," Brian said. He waited until the boy had eaten the cookie and then he asked. "What's your name?"
"Simon," the boy said. "Simon Newbury." Brian saw the boy eyeing Brian's pocket, and Brian gave him a second cookie.
"How long have you been on your own?" Brian asked.
"I don't know. A long time," the boy said. "Mum's dead. Dad went out one night to find out what the noise was inside the house, and, well,...he just never came back. When I ran out of food, I left. I've been trying to find him, but, well, I ran out of money too. And...the aurors were chasing me, so..."
"What were they chasing you for?" Brian frowned. The boy hesitated, realizing he'd said too much. "I'm not going to turn you in. What did they want?"
"I stole a loaf of bread from a place in Diagon Alley. It was fresh baked. Smelled so good. One of the people having some sort of fancy coffee drink saw me and shouted to a couple aurors at another table..."
"Wait...Did this place have little sparkling animals?"
"Up on the ceiling they did. Butterflies I think it was. Or birds. Why?"
"There'll be no issue over the bread," Brian smiled. "I can get that cleared up for you. Now--how about we get you back and find you a hot bath, some warm and dry clothes and a proper meal?"
"How do I know I can trust you?" the boy narrowed his eyes at Brian.
"Do you have much of a choice?" Brian asked. "You're welcome to stay out here, starve or die of exposure--or you can come with us." The boy scowled at Brian, not liking Brian's candor, but as Brian saw it, honesty appeared to be the best choice for right now.
"Oh, fine," the boy sighed, realizing Brian was right.