Bruce had been helping one of the younger students with some particularly confusing passages of their homework reading in the common room when Sherlock had stormed out of the dorms. He would have followed to figure out what was bothering his friend but it was getting close to curfew for the younger students and he wanted to make sure they got all the help they needed from him before they had to get to bed. He figured he could try tracking down the errant detective-wannabe through the journals once he got to his room, so, after bidding the kiddies good night he made his way up to the sixth year floor.

When he found Tony scrabbling around the floor, he just frowned. When he saw the bruise forming on his jaw, he put 2 and 2 together, sighed, and approached the young stupid genius. "What did you do to Sherlock?" he asked wearily as he dropped to a knee in front of the younger boy, hand automatically reaching for his face to examine the damage.