The Office

Did someone come up in the elevator from the ground floor or the basement? Was it someone in one of the offices who went up to the roof? Either way, it’s possible to get to the rooftop via the northwest stairway without being seen, as long as you don’t walk by the open reception area when Annette Su Ling is there. Coming from one of the offices, someone might have to pass in front of another office, but, hey, if you were deeply engrossed in reading this when someone whisked by your door, would you necessarily see them or know who walked by?