DM: Check your brother's office.

Might as well - you even actually have a key for his office! You head over to his office, and... is he here? His door is open, his lights are on, his computer's on, and his desk is a bit of a mess. Well, you don't think it's that bad, but he certainly would! You guess that'd explain why the office lights are on at 1 in the morning, but why would he be working so late?