After one millisecond of tension that Greg might be taking on too much just to "be a hero," it turns out... the Professor just did all the work for him. What?? Are there only three floors? How did he empty the entire building? Wasn't everyone asleep? I guess everybody else is a much lighter sleeper than Margo. Hey wait, I'm not seeing any hilarious sound effects for the fire detectors. Or any sprinkler system, for that matter! Hey, who owns this building anyway?