Sarah Douglas - best known for her role of Ursa in the Superman movies - takes on the iconic role of Dorothy Parker in the third episode: David Llewellyn's Murder on 81st Street. Set in 1930s New York, Dorian and Dorothy are unexpectedly reunited, and immediately find themselves thrust into a supernatural murder mystery... where they're both inching towards the top of the suspect list!

'It's always a joy to have Sarah in studio,' says director Scott Handcock. 'She has such a dry sense of humour and turn of phrase, I knew she was the only person who could truly do David's script justice. And the chemistry that she and Alex share is brilliant. They're like an old married couple: genuine affection, but unafraid to puncture the other's ego from time to time. It's a fun new dynamic!'

Hugh Ross - who Big Finish fans will recognise as Sir Toby in Counter-Measures -  stars in the fourth episode: The Immortal Game by Nev Fountain.

'Alex and Hugh worked together on the John Simm version of Hamlet,' explains Scott, 'and - quite understandably - Alex has been asking if we can get him into the series ever since. I've been waiting for the right part - and then two came at once! Only Hugh could play multiple members of a single family and make them sufficiently similar but wildly different at the same time. He has menace and charm and melancholy... it's a wonderfully unpredictable performance in a play that keeps you guessing!'

Other guest stars for the series include actors David Menkin, Jolyon Westhorpe, Thomas Rees-Kaye and Louise Faulkner, with appearances from Miles Richardson, Marcus Hutton, Paul Jones and James Unsworth.

The five-part series is available to pre-order now ahead of its release from late July, on download for just £2.99 an episode, or £12.99 if you subscribe to the entire series. An adaptation of Oscar Wilde's original novel The Picture of Dorian Gray is also in production, and an hour-long Halloween special will follow in October.

Don't forget - you can also follow the series on Twitter @DorianGrayBFP for the latest news, competitions and updates!