Holmes' "Why?" assailed Doctor Watson as soon as he entered the apartment.

"What's that, Holmes? Well, I'm late because little Mrs Bentley insisted-"

"No, no, Dr Watson, I would not presume to ask about your lateness - today, at least," Holmes continued, noticing Dr Watson's raised eyebrows.

"Indeed my question refers to the movements of a certain young woman attired like a servant but with the hands and bearing of a refined young lady. Most concerning is the fact that she appears to have attached herself to the newspaper boys as they ply their trade on the street corner opposite, yet her attention seldom leaves this window!"

Edging closer to the window, Dr Watson stood shoulder to shoulder with his good friend to look from the opposite side of the heavy drapes to the street below.

"No, Holmes-"

"No, my good man?"

"Let me finish, Holmes; I believe the young lady, rather than looking towards this window is, in fact, giving her attention to the window of the apartment next door!

"Reaching towards the desk, Holmes arched an eye towards Watson as he grasped his telescope in his hand.

"Let me see, tilt of her cap, angle of her chin and her shoulder- well done, Watson. I believe you are quite correct. It was altogether the side angle at which she wore her cap; most unusual, most unusual."