Over the next eight weeks, previously unexplored mysteries from the career of Victorian England’s greatest detective will finally be revealed, in the serialised adventure Sherlock Holmes Untold. 

Each Wednesday will see the release of a new half-hour, full-cast audio drama episode, starring Nicholas Briggs as the deductive genius Holmes and Richard Earl as his friend and confidant Doctor Watson. 

Over the series, listeners will discover six cases from across Holmes’ lifetime, each having been referred to – but not fully explored – in one of Sir Arthur Conan Doyle’s canonical stories. And through it all, a greater conspiracy will emerge… 

The story begins today in The Adventure of the Remarkable Worm - Part One. In 1913, on a train hurtling across England, Doctor Watson encounters prime minister Jasper Cranfield (Christopher Naylor) and his secretary Rosborough (Luke Barton), and begins recounting a case from many years before. 

Sherlock Holmes Untold is now available to purchase for just £24.99, exclusively here. This purchase will grant you access to all eight weekly episode downloads, as well as the complete serial as a download to own box set once all episodes have been released. 

The Adventure of the Remarkable Worm - Part One 

Late November, 1913. A train cuts haughtily across the English countryside. On board: Dr John Watson, the British Prime Minister and a certain tin box, full of accounts and mysteries which have long been too shocking, too scandalous and too dangerous to be told to the public – until now! 

Sherlock Holmes Untold: The Adventure of the Remarkable Worm - Part One guest stars Jason Forbes as fragile journalist Isadora Persano and Vineeta Rishi as his cunning sister Frances Persano. 

Lead actor Nicholas Briggs said: “What we have here are eight different episodes of Sherlock Holmes, all part of the same story, but they all have distinct little plots as well. It all fits together, and there are many clues to pick up along the way. 

“What’s so lovely is that we’re doing this serialised version to recapture the spirit of the old Strand Magazine stories, and also to make a bit of noise about Sherlock Holmes and experiment with what it’s like to do a series released on a weekly basis.” 

Writer Jonathan Barnes added: “This first two-part story comes from a reference in Doyle’s The Problem of Thor Bridge to the well-known journalist and duellist Isadora Persano, who was found stark staring mad, staring at a worm in a matchbox that is unknown to medical science.  

“It’s a fantastic image, great idea, and a good example of Doyle’s sense of humour – something quite deliberately bizarre. So this is an attempt to tell that story, and we had a lot of fun with it, coming up with our own answers to the questions that Doyle asks.” 

There will be an ‘after show’ discussion for this episode in this week’s edition of the Big Finish Podcast, due to be released on Friday, with special guests Jonathan Barnes, Nicholas Briggs, and Richard Earl, as well as Michael Barnes and Mark Jones from the Sherlock Holmes Society of London. 

The podcast’s producer and presenter Iain Meadows said: “Our podcast is a look at this groundbreaking series, which takes the adventures of the great consulting detective into new territory, namely those cases that Watson has never before dared to reveal, and perhaps for good reason. 

“We delve into each episode with a host of guests from cast to crew, alongside our listening panel from the Sherlock Holmes Society of London, who will help me unpick the mystery of mysteries through these episodes. There’ll be some thought-provoking ideas shared along the way, and twists in the tale revealed. In short, if you think you know your Holmes, think again!” 

Next week on Sherlock Holmes Untold, the conclusion of this first mystery from Holmes’ forgotten casebook is revealed, and the closing moves are made in a larger game, in The Adventure of the Remarkable Worm - Part Two. 

Sherlock Holmes Untold is now available to purchase for just £24.99 as a series of digital downloads to own, released weekly exclusively from www.bigfinish.com.

All the above prices (including pre-order and multibuy bundle discounts) are fixed for a limited time only and guaranteed no later than 31 January 2026.