He paused momentarily at the window, watching the man across the street.
The man, who was dressed in an expensive suit, was obviously agitated. He had rushed to come to the address and was now standing with his back against a shop window, catching his breath. He was checking the time and looking up at the detective agency. It was evident that he considered it important to arrive at the office on time. The man seemed to be twitching, continually looking around nervously from time to time. Together, all of these things pointed to a person who was in serious trouble. He was living on his nerves. Beneath this there was a reluctance to turn to a stranger. The observer noticed these things in his line of work.
After a couple more minutes and checking the time again, the man carefully crossed the street, straitening his tie as he came forward to the entrance. The man at the window nodded with satisfaction seeing that the visitor was intent on giving a good impression. He could tell. He could also determine that it was a very personal and possibly embarrassing mission that had brought him here.
Minutes passed, before the elevator squealed behind him. The doors slid open and the gentleman in question emerged at the end of the long hall, looking around.
He said, “The Investigations Agency?”
The man at the window said, “Along the hall, second door on the left.”
As he watched him go he smiled knowingly.
He dropped his chamois leather into the bucket, squeezed it out and went back to cleaning the window.