What sort of a person walks into a college accomodation at 3:20 in the morning, wanting to ask about course details?
This isn't a rhetorical question, btw. It's genuine. Because the only explanations I can come up with for that, and the surrounding sequence of events, is a deeply unpleasant one.
Two men. Locals, by the accent. Driving a very nice car, without the diction or age to suggest they acquired it legitimately. Stayed outside in the car for a good 15 minutes, did a sweep of the street before entering. We don't realise they're not our students, let them in. They start asking questions: is this a college, what courses do you provide? When we explain it's not, just the accomodation, they start asking about the ages. They then bugger off. Sit in the car another 10 minutes, finally leave.
Had a friend outside, too. Spoke to him as they walked down the street. Friend didn't arrive in the car with them though, or leave.
IMO, they were clearly casing the joint. Check for activity on street, CCTV. Same for the outside, and reception, of this building. Go inside to see what kind of personnel and security are present. Notably they did not enter the University College London accomodation, just two buildings down from here.