I love the way this story begins — not with a scream or a chase, but with a quiet Tuesday morning in Baker Street and a single walking stick left behind on the sitting-room table. Holmes and Watson are alone, their mysterious visitor having already come and gone without meeting them. All that remains is this wooden cane, worn and scratched, with a silver band engraved with initials and a date. It sounds like almost nothing. And yet, watching Holmes turn it over in his long fingers, I get the feeling we are about to see something extraordinary.

Watson, eager to show off, goes first. He squints at the stick and does a reasonable job, actually. He guesses the owner is a successful, well-liked country doctor — the kind of man who gets presented with gifts by grateful patients. He notices the stick is well-worn, suggesting someone who walks a great deal. Not bad at all! But then Holmes steps in, and the whole room seems to sharpen. Holmes points out details Watson simply walked past: the calluses implied by the grip, the particular wear pattern that suggests long treks across rough ground, and — my personal favourite bit — the tooth marks near the base of the stick. A dog has been chewing it, and the spacing of the teeth tells Holmes the animal is a medium-to-large breed, probably a spaniel.

What I find so thrilling about this opening is that Holmes is not showing off for the sake of it. He is teaching Watson — and teaching us — how to truly look at the world. Every object carries the fingerprints of its owner's life. By the time Mortimer actually walks through the door, Holmes can greet him almost like an old acquaintance, because the stick has already told its story. It is a perfect little magic trick, and it sets the tone for everything that follows: in this book, the truth is always hiding in plain sight, waiting for someone patient enough to notice it.