The Doctor and Peri are reunited with an old friend – or is he an enemy? Turlough insists he’s changed since they last met. The trouble is, so has the Doctor, and he’s not inclined to trust his one-time companion. 

As they travel through Stuart England, Medieval France and Viking Denmark, can they forge a new relationship – or will Turlough’s secrets force them further apart? 

Listeners of The Sixth Doctor Adventures were surprised at the end of August 2025’s box set, Bad Terms, when the Doctor (Colin Baker) and Peri (Nicola Bryant) found themselves reunited with an old travelling companion, Vislor Turlough (Mark Strickson). 

Turlough’s time with the Fifth Doctor – as seen on TV Doctor Who from 1983 to 1984 – was tempestuous, as he spent much of it in league with the Black Guardian, plotting against his Time Lord friend. How will the Doctor deal with a supposedly matured Turlough, and how will Turlough deal with a regenerated Doctor? 

All will be revealed across the two box sets of The Sixth Doctor Adventures due to be released in 2026, beginning with April’s Expulsion, which takes the time-travelling trio to three dangerous points in Earth’s history… 

Doctor Who – The Sixth Doctor Adventures: Expulsion is available to pre-order now for just £19.99 (download to own) or £24.99 (download to own + collector’s edition CD), 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 three adventures for the time-travelling trio are: 

The Reckoning by Nev Fountain

When the TARDIS is stranded in the path of a neutron star, the Doctor, Peri and Turlough have to flee. They end up in seventeenth-century London, where another old friend, Christopher Marlowe, is trying to get out of a pact he’s made. 

Marlowe’s soul is on the line – but has Turlough also made a deal with the Devil… again? 

A Crucible of Queens by Lizbeth Myles 

In the aftermath of the Battle of Agincourt, the Doctor and Turlough find themselves aligned with opposing factions. Turlough befriends Charles, the Dauphin of France, while the Doctor is tasked with healing his father, King Charles VII. 

But two powerful women are also in play: the dauphin’s advisor Yolande, Duchess of Anjou, and his estranged mother, Isabeau of Bavaria. Can the TARDIS crew keep both queens happy – and keep their own heads? 

The Curse of the Duergar by Julian Richards 

Shieldmaiden Hervor braves the ghosts of her ancestors to claim her birthright, the sword Tyrfing. Made by the Duergar, the Dwarf kings of the below, the blade is cursed: once drawn, it must kill. 

Even the Doctor cannot resist the power of the sword, and to the horror of Peri and Turlough, he is forced to take a life… 

The guest cast of The Sixth Doctor Adventures: Expulsion includes Debbie Chazen (The Smoking Room, Mine All Mine) as Isabeau of Bavaria, Julie Dray (Crashing, Avenue 5) as Yolande of Aragon, and Lara Lemon (Insomnia, The Drowned) as Hervor, plus further names to be announced. 

Producer Jacqueline Rayner said: “This is a really exciting set for me – three fabulous historical stories plus some deep-diving into the psyches of the TARDIS regulars following the surprise (at least I hope it was a surprise!) reunion at the end of the previous boxset.” 

Script editor Robert Valentine added: “The Doctor and Peri suddenly have a new and unexpected TARDIS-mate, but he’s someone they’re both already familiar with: Vislor Turlough. Yes, Turlough is back, but he's got some brand-new secrets, and he’s having a hard time deciding if he can trust this brash Sixth Doctor the way he finally came to trust the Fifth. 

“We’ve got three terrific writers on this set: Nev Fountain, Lizbeth Myles and Julian Richards, and helping them bring Turlough back into the fold for an epic arc has been huge fun. The Doctor, Peri and Turlough’s new adventures take them from Elizabethan England to dark age Denmark via the fallout of the Battle of Agincourt, but Earth’s troubled history is hardly more turbulent than their own.” 

Big Finish listeners can save money be pre-ordering Expulsion in a multibuy bundle with 2026’s second Sixth Doctor Adventures box set (title TBC, due for release in August) for just £38 (download to own) or £47 (download to own + collector’s edition CD box set). 

Alternatively, listeners can buy this release 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). 

All the above prices (including pre-order and multibuy bundle discounts) are fixed for a limited time only and guaranteed no later than 30 June 2026. 

Big Finish is currently operating a digital-first release schedule. The mailout of collector’s edition CDs will be delayed, 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.