When the Doctor isn’t around to save the planet, the brave soldiers and scientists of UNIT step up to the challenge. The audio drama box set UNIT Eras: Hostile Universe comprises four brand-new stories set throughout the history of the Unified Intelligence Taskforce. 

These stories take in classic era UNIT figures such as Sarah Jane Smith (Sadie Miller) and Brigadier Lethbridge-Stewart (Jon Culshaw) as well as twenty-first century heroes like Kate Stewart (Jemma Redgrave) and Osgood (Ingrid Oliver). 

There’s also the first ever full-cast audio adventure set in the Fifteenth Doctor era of Doctor Who, and the Big Finish debut of Colonel Mace (Rupert Holliday-Evans) – something for every UNIT fan! 

The Worlds of Doctor Who – UNIT Eras: Hostile Universe is now available to purchase as a digital download to own for just £24.99, exclusively from www.bigfinish.com. 

The four brand-new audio episodes set across UNIT's history are: 

Rise of the Valiant by Andrew Smith 

2008. The Earth has been stolen and planets fill the sky.  

With the Doctor otherwise engaged, it falls to UNIT’s finest – Colonel Mace, Harry Sullivan, and the retired Brigadier Lethbridge Stewart – to take the fight back to the Daleks. Because deep in the Brazilian rainforest, a secret weapon with a familiar name is waiting. And it’s ready to fly. 

Rise of the Valiant stars Jon Culshaw as Brigadier Lethbridge-Stewart, Christopher Naylor as Dr Harry Sullivan, Rupert Holliday-Evans as Colonel Alan Mace, Meghan Treadway as Major Zara Webber, Ines Amado as Chief Engineer Aurea De Silva, and Nicholas Briggs as the Daleks. 

On returning to the character of Colonel Mace for the first time since 2008’s TV episodes The Sontaran Stratagem and The Poison Sky, Rupert Holliday-Evans said: “I thought he was lost to history! But I’ve always wanted to come back. Mace is a leader of men, but he cares for all his people. He’s concise. He’s strong. And there’s a good sense of humour to him as well.” 

The Indigo Child by Ken Bentley 

2017. UNIT has been shut down, its heroes targeted. 

After an attempt on her life, Kate Stewart fights from the shadows, doing what she can to protect the people of Great Britain. Reunited with Petronella Osgood, Kate goes undercover to save a child refugee with psychic powers. It’s a race against time, and a new enemy is determined to win. 

The cast of The Indigo Child includes Jemma Redgrave as Kate Stewart, Ingrid Oliver as Petronella Osgood, Natalie Gumede as Angela Rukundo, Julie Teal as Woman with No Name, Alan Cox as Nathan Favager, and Robert Whitelock as Edwards. 

Jemma Redgrave said: “This story fills in the gap between when Kate’s sacked by Prentis and her house blows up and the next time we find her in the Jodie Whittaker iteration of Doctor Who. It’s brilliant to know what she’s been up to in that time. It’s a great adventure, funny and exciting and thrilling. The partnership between Kate and Osgood is magical.” 

The Life and Death of Private Eddie Wise by Hannah Kennedy 

The dawn of UNIT. Aliens have invaded and Eddie Wise is far from ready. 

Plagued by nightmares and lying to his fiancé, the beleaguered Eddie becomes embroiled in a plot to bring his workplace to its knees. To make matters worse, there’s a journalist on his tail. Because Sarah Jane Smith needs the scoop on UNIT, and Private Wise might just be the man she needs. 

This episode stars Sadie Miller as Sarah Jane Smith, Jon Culshaw as Brigadier Lethbridge-Stewart, George Somner as Private Eddie Wise, Elaine Tan as Lynn Prentice/Lynn’s Sister, Lois Chimimba as Lance-Corporal Maggie Bradfield, Angus Imrie as Private Chris Hutchinson/Private Colin Bartlett, and Jonathan Keeble as Barry Buckingham/Horace Otter. 

Sadie Miller said: “This feels very modern and very relevant to issues that are vital now even though it is set in the 1970s, and what first struck me was just how moving the script is. Sarah is still quite young at this stage, very gung-ho and not afraid of taking risks, and one of her great strengths is her empathy – she forms an attachment to Eddie in almost a sibling way.” 

Deadstar by Joshua Pruett and Jonathan S Powell 

2023. The Toymaker has been vanquished and UNIT stands tall. 

But when a cutting-edge telescope is brought online, the UNIT skyscraper is plunged into lockdown. Besieged by an impossible foe, Melanie Bush, Colonel Alec Grover and new recruit Dr Isla Ellis need all their wits to survive. Because the stars have woken up, and something is very wrong with the Vlinx. 

The cast of Deadstar comprises Bonnie Langford as Melanie Bush, Adam James as Colonel Alec Grover, Nicholas Briggs as the Vlinx, Danielle Bird as Dr Isla Ellis, Luke R Francis as Eric Lane/Trooper 1, Claire Wyatt as Mother/Trooper 2, and Jemma Redgrave as Kate Stewart. 

Bonnie Langford said: “This is exciting, because this is Mel working at UNIT in her own capacity, and she gets to be more in charge of her own adventure. She rises to the challenge, but often shows her vulnerabilities in the meantime.” 

The Worlds of Doctor Who – UNIT Eras: Hostile Universe is now available to pre-order as a digital download to own for just £24.99, exclusively here. 

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.