Let's set the scene. We're in a modest Parisian neighborhood. A reclusive old man, Monsieur Méchinet, is found dead in his locked apartment. The local police inspector, a man named Gevrol, takes one look and declares it a clear suicide. Case closed. But a young, ambitious policeman named Monsieur Lecoq isn't so sure. The evidence feels off. Why would a man shoot himself, then carefully hide the gun? How did he lock the door behind him? Lecoq convinces his superiors to let him investigate, and he starts digging into the life of the 'little old man.'

The Story

The plot follows Lecoq as he methodically interviews the dead man's neighbors—a nosy concierge, a nervous seamstress, a suspicious-looking stranger. Everyone has a different story. He uncovers a recent inheritance, a missing key, and hears reports of a mysterious visitor on the night of the murder. The brilliance of the story is in the details. Gaboriau shows us every step of Lecoq's process: measuring distances, examining dust, and questioning assumptions. It's a battle of wits between Lecoq's modern, logical approach and Inspector Gevrol's lazy conclusions. The solution, when it comes, is satisfyingly clever and hinges on a simple, overlooked trick.

Why You Should Read It

This book is a treat because it lets you watch the detective genre being built, brick by logical brick. Monsieur Lecoq isn't a superhero; he's a working cop who uses observation and deduction. You feel like you're solving the puzzle alongside him. Beyond the mystery, the book is a snapshot of everyday Parisian life. The gossipy neighbors, the cramped apartments, the social tensions—it all feels real and lively. Gaboriau has a knack for quick, vivid character sketches that make even the minor players memorable.

Final Verdict

This is a must-read for any mystery fan who wants to visit the roots of their favorite genre. It's perfect for readers who enjoy Agatha Christie's puzzles or Arthur Conan Doyle's deductive reasoning and want to see where those ideas came from. It's also a great, short pick for someone who thinks 'classics' are stuffy—this one moves at a good clip and has genuine surprises. If you like your mysteries clever, character-driven, and free of gore, you'll find a real friend in this little old book.