All irregularities will be handled by the forces controlling each dimension. Transuranic, heavy elements may not be used where there is life. Medium atomic weights are available: Gold, Lead, Copper, Jet, Diamond, Radium, Sapphire, Silver and Steel. 

Sapphire and Steel have been assigned. 

Sapphire & Steel, created by P. J. Hammond, was originally broadcast between 1979 and 1982. It starred Joanna Lumley and David McCallum as a pair of “interdimensional operatives” tasked with protecting the flow of time. Each story would see them take human form as they showed up in a new location, to investigate a dangerous anomaly. 

Between May 2005 and August 2008, Big Finish released 15 full-cast audio dramas based on the TV series. The late David Warner took on McCallum’s part to play the stubborn Steel, whilst Susannah Harker slipped into Lumley’s role as Sapphire. 

For three of the audio stories, original TV guest star David Collings returned to recreate his performance as Silver. Other notable guest stars in the range included Mark Gatiss, Colin Baker, Sarah Douglas, Richard Franklin, Angela Bruce, Arthur Bostrom and Louise Jameson. 

The audio series was only ever released on CD and has been unavailable for more than a decade.  

Now, in association with ITV Studios, all three series have been re-released as downloads, giving fans the chance to relisten or indeed discover the adventures for the first time. 

Each series comes packaged with a brand-new 30-minute behind-the-scenes featurette, offering an insight into the production of these beloved adventures. 

All three series are available to buy at an exclusive early-bird price for the first month; Series One (comprising five stories) is available for just £19.99, Series Two (comprising six stories) is just £24.99, and Series Three (four stories) is £19.99. 

Big Finish chairman Jason Haigh-Ellery said: “We are delighted to have reached an agreement with ITV Studios to bring back our Sapphire & Steel releases as downloads. We have received regular requests over the years for it to be made available again, so we’re pleased that a whole new generation of listeners will be able to hear the late, great David Warner as Steel and Susannah Harker as Sapphire.” 

Nigel Fairs, who produced the series, added: “I’m absolutely delighted that people will be able to hear our version of Sapphire & Steel again, as it really was a labour of love. Re-imagining such a visual television series for audio was no easy task, but I think my decision to concentrate on the emotional story arcs of the characters who encountered ‘Time’ and our two agents bore some really tasty fruit! Dear David and Susie were the perfect leads, and the recording sessions were amongst the happiest I ever had at Big Finish. Creative times indeed. ‘Roll back time, Sapphire…’” 

The four-part stories in each series are: 

Series One: 

• The Passenger by Steve Lyons

• Daisy Chain by Joseph Lidster 

• All Fall Down by David Bishop

• The Lighthouse by Nigel Fairs 

• Dead Man Walking by Nigel Fairs (based on a story by John Ainsworth) 

Series Two: 

• The School by Simon Guerrier

• The Surest Poison by Richard Dinnick

• Water Like a Stone by Nigel Fairs

• Cruel Immortality by Nigel Fairs 

• Perfect Day by Steve Lyons

• The Mystery of the Missing Hour by Joseph Lidster

Series Three: 

• Second Sight by Nigel Fairs

• Remember Me by John Dorney

• Zero by Steve Lyons 

• Wall of Darkness by Nigel Fairs 

All three series are available exclusively here. Series One is available for just £19.99, Series Two for £24.99, and Series Three for £19.99. 

All the above prices include the special pre-order discount and are subject to change after general release.