The Locked Room (The Baker Street Mysteries #3)

The Locked Room (The Baker Street Mysteries #3) by Holly Hepburn is out now (published January 20, 2026).

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The Locked Room (The Baker Street Mysteries #3) Release Date: January 20, 2026

Published

The BRAND NEW instalment in Holly Hepburn’s Baker Street Mystery series! 🔎✨

Join Harriet White in 1930’s London for another glorious Sherlock Holmes-inspired mystery, for fans of Helena Dixon, Nita Prose and Janice Hallett 🕵️‍♀️

Harriet White is settling into life in the post room of the Baker Street building society. Until she discovers a letter in The Times challenging Sherlock Holmes to prove his status as the world’s greatest detective by solving an impossible mystery.  The letter, signed Professor James Moriarty, advises Holmes that the crime will be committed within the next seven days. Holmes himself must deduce which crime is the correct one to investigate. Dismissing the letter as a prank – after all, Sherlock Holmes isn’t real – Harry goes about her business. But then news breaks of the theft of valuable diamond from a safe in an apparently locked room in a Mayfair townhouse…

Intrigued in spite of her misgivings, Harry dons a disguise and investigates. But as she begins to unpick the puzzle, a body is found.

And now, a stranger, and far more deadly mystery begins to unfold around her. Can Harry solve the case before the killer strikes again? 👀 

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Genre: Cozy Mystery

Holly Hepburn

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Book Club Journal: Reading Log For Adults & Kids Who Love Books!
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