Antoine had been out on the town that morning, making sure to order a few new coats for himself and Aimé. He couldn't have people looking at them badly because they wore out dated clothing. It wouldn't help them achieve their goal at all. His mind on the items that he'd purchased and making a mental note to tell the servants to be expecting them. It would be a surprise for his brother - he hadn't even told him about them, but he was in the mood to be nice, so he knew that Aimé wouldn't complain.
Lost in his own little world as he was, he wasn't really paying attention to the patrons on either side of him. He'd passed by the store window and was almost to the store that he was going to patronize for his next purchase when he heard the young girl scream.
Turning to see what was the cause of the ruckus, he spotted a girl that had been knocked down - she looked very familiar, but he couldn't figure out why - and realized that the boy running in his direction had stolen her purse. Without thinking about it, he reverted to his old habits and extended his leg to trip the boy.
When he was on the ground, Antoine used his weight to take the bag back from him. Pressing his weight into him, he waited until the boy stopped fighting back before standing up. "Do not ever accost a young lady again." Ignoring him now that his point was made, he carried the purse back to the girl and extended his hand to help her up.