The Third Doctor (Tim Treloar) has plenty of dangers to face in his latest adventure, The Imposters by Alan Barnes, but he’s joined by a number of his friends, including dogged journalist Sarah Jane Smith and impeccable scientist Liz Shaw. 

This marks the first time that Sarah Jane and Liz have appeared in an audio adventure together; these fantastic companions are played by Sadie Miller and Daisy Ashford, the daughters of original TV series actresses Elisabeth Sladen and Caroline John, respectively. 

But their first meeting’s not a social one... Together, the Doctor, Sarah and Liz – along with Brigadier Lethbridge-Stewart (Jon Culshaw) – must uncover a complex case involving top-secret technology gone missing, superstar wrestlers, and knights from outer space. 

Doctor Who – The Third Doctor Adventures: The Imposters is now available to purchase for just £19.99 (download to own) or £24.99 (download to own + collector’s edition CD box set), exclusively here. Please note: the collector’s edition CD box set is strictly limited to 1,500 copies and will not be re-pressed. 

The Doctor and the Brigadier are on the trail of stolen, advanced technology. Sarah Jane Smith is convinced an informant is leading her to a top-secret space tracking station. And Dr Elizabeth Shaw is wearing a metal helmet, covered in tin foil. 

It’s a deadly puzzle, involving a precocious schoolgirl, a Saturday night all-in wrestling star and a high-ranking military officer. There’s a plot to control the Earth’s weather and somewhere in all this, there’s a connection to the constellation of Centaurus. 

To defeat an enemy with no regard for human life, the Doctor must battle on all fronts, but not before a lethal encounter with the Venusian karate Downward K-klak!
 

The guest cast of The Imposters also includes Grace Darling as Jessamine Curbishley, Gary Turner as the Minister, Simon Kane as Sam Samsonson, Mark Elstob as Major-General Maupassant/Wrestling Commentator, Samuel Clemens as Lieutenant Gurney, Lara Lemon as the Arbiter/Headmistress, and Miranda Barnes as Knights/Annabel. 

Lead actor Tim Treloar said: “This story is very exciting. It’s so full of humour. Alan’s scripts are always brilliant and very easy to perform. Working with Sadie and Daisy at the same time, what a handful – double trouble! It’s lovely acting alongside both of them.” 

Daisy Ashford, who plays Liz Shaw, added: “It’s different from other stories I’ve worked on because it’s essentially a Sarah Jane story that Liz has stumbled upon. But there’s something liberating about that for Liz, in that she’s not tied to this team and yet she slips into it nicely. 

“It’s been brilliant working with Sadie. We get on terribly well, but we’ve never actually been in studio together before. She sounds so much like her mum and it’s just wonderful to watch her work.” 

And, Sadie Miller, the voice of Sarah Jane Smith, said: “Getting Sarah and Liz together is something that I’ve been waiting for for a long time. It’s been lovely working with Daisy, getting to hear her in person. I’ve listened to some of Daisy’s audios and I think she sounds so like her mum, but to hear it in person is lovely.” 

Praise for the previous Third Doctor Adventures volume, Operation: Vengeance: 

“A masterpiece… rich in its realistic historical themes, strong performances, and emotional moments.”
The Doctor Who Companion 

“The badinage passing between alien and army officer is as sparkling as one would hope.”
Doctor Who Magazine 

“Genuinely marvellous.”
Tin Dog Podcast 

Big Finish listeners can save money by purchasing The Imposters in a bundle with 2026’s second Third Doctor Adventures box set (Title TBA), due for release in October 2026, for just £38 (download to own) or £47 (download to own + collector’s edition CD box set).  

Alternatively, listeners can buy this series as part of a bundle of all 15 Classic Doctor Who box sets released in 2026 for just £285 (download to own) or £352.50 (download to own + collector’s edition CD box set). 

Please note that Big Finish is currently operating a digital-first release schedule. The mail-out of collector’s edition CDs may be delayed due to factors beyond our control, but all purchases of this release unlock a digital copy that can be immediately downloaded or played on the Big Finish app from the release date.