Beat Around the Storeroom

After realizing all these henchmen and/or henchwomen (it's hard to tell in those stalker outfits) have been in the same block of hallways, you're able to focus your search. As you search, you overhear some of the students talking about picking something up from the unlocked storeroom.

Sounds like just the lead you need! Or maybe they're looking for cleaning supplies, but if you know college students they're way more likely to become supervillains than mop.