Based on the context and the answer, generate a question. 

Context: He 'd clean one window then would edge his way along the ledge to the second one . For a short while in doing this , he 'd disappear from view . I was busy brushing jackets and setting up the department for the day when I realized the window cleaner had been out of sight for about five minutes . It was a far drop from my floor to the street below and I feared the worse ; I opened the window and peered down into Gabriels Hill . No blood splattering . I turned my head to the right and there was the window cleaner frozen between the two windows .

Answer:

He has suddenly become scared of how high up he was .



Why had the window cleaner been between the two windows for so long ?