The Unified Intelligence Taskforce, ever since it was founded in the mid-20th century, has built up a reputation for protecting the Earth from alien threats, of all shapes and sizes, through military might and scientific ingenuity. 

UNIT has been a recurring feature in Doctor Who since 1968, and also took centre stage in recent TV spin-off The War Between the Land and the Sea. The brand-new audio series UNIT Eras, which begins in April with the box set Hostile Universe, follows the previously untold exploits of heroes from across those decades. 

There are new adventures for early UNIT figures like Brigadier Lethbridge-Stewart (Jon Culshaw) and Sarah Jane Smith (Sadie Miller), as well as more recent faces like Kate Stewart (Jemma Redgrave), Osgood (Ingrid Oliver), and Melanie Bush (Bonnie Langford). The box set also features the Big Finish debut of The Sontaran Stratagem’s Colonel Mace (Rupert Holliday-Evans). 

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. 

The four full-cast audio adventures 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, and Nicholas Briggs as the Daleks. 

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. 

This episode’s cast is led by Jemma Redgrave as Kate Stewart and Ingrid Oliver as Osgood. 

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 George Somner as Private Eddie Wise, Sadie Miller as Sarah Jane Smith, and Jon Culshaw as Brigadier Lethbridge-Stewart. 

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. 

Deadstar’s cast includes Bonnie Langford as Melanie Bush, Nicholas Briggs as the Vlinx, and Jemma Redgrave as Kate Stewart. 

Script editor Jonathan S Powell said: “I love UNIT, it’s one of my favourite bits of Doctor Who – all those classic 1970s adventures and the fact that it runs through the whole show from then to the present day. It’s quite an exciting prospect to be able to showcase all of that in a single set, UNIT through the ages. 

“I’m really proud of UNIT Eras. It’s been one of the most difficult jobs that I’ve had with Big Finish, because each individual episode is a universe all of its own, and you want to do justice to an era, make it sound and feel right, as each will be someone’s favourite era of UNIT.” 

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.