Following a trail of clues at Aldgate station, Holmes makes a stunning discovery that leads to an unexpected twist in the investigation.

Now convinced that Cadogan West’s death is part of a greater international conspiracy, Holmes asks Mycroft to send him a list of all the foreign spies residing in London.

Soon, the master detective uncovers the most likely suspect but he needs proof — and the only way to get it is by orchestrating a daring break-in. 

A Noiser production, written by Sir Arthur Conan Doyle.

Narrated by Hugh Bonneville

Produced by Katrina Hughes and Addison Nugent

Sound Design and Audio Editing by Miri Latham, Anisha Deva and George Tapp

Compositions: Dorry Macaulay and Oliver Baines

Mix & Mastering:  Cody Reynolds-Shaw and Liam Cameron

Series Consultant: Dan Smith

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