A mutant? She looked normal enough. She didn't have tentacles or like an extra eye in the middle of her forehead. Maybe she was like one of those M-Men mutants where she could do something special without looking weird.
He thought about it for a moment, there had definitely been time spent in her room, but she didn't seem to need an explanation. "Yeah, and maybe Julie, I don't know. We don't have other visitors, so you shouldn't smell anyone else." My roommate Julie is at work, but I'm sure she won't mind if you smell her stuff too, you know, if you need to be able to tell the difference. We're both worried."