I gave the letter a quick once-over. It read:
Dear Roberta: A few days after you receive this, you’ll have a call from Archibald C. Smith of Chicago. I’ve given him your name. For business reasons, I wish you’d be particularly nice to him and make his stay in New Orleans as pleasant as possible. Show him around the Quarter and take him to some of the famous restaurants. I can assure you it will be bread on the waters, because—
I heard the door opening from the corridor, heard a man’s voice saying, “All right then, that’s a promise! Don’t forget, now.”
I tossed the letter back to the table and was putting a match to my cigarette when Roberta Fenn came back.
She smiled at me, said, “Well, let’s see. Where were we?”
“Nowhere in particular,” I said. “Just talking.”
She said, “You’re a detective. Tell me how that man could have got through the street-entrance door without ringing my apartment.”
“That’s easy.”
“How?”
“He could have rung one of the other apartments, got a signal to come in, and then gone up. Or he could have picked the lock on the lower door. The locks on those street doors don’t amount to much. They’re made so that the key to any apartment will open them. Why would he want to get in without giving you a ring?”