Simon Guerrier is a British science fiction author and dramatist, closely associated with the fictional universe of Doctor Who and its spinoffs. Although he has written three Doctor Who novels, for the BBC Books range, his work has mostly been for Big Finish Productions' audio drama and book ranges. Guerrier's earliest published fiction appeared in Zodiac, the first of Big Finish's Short Trips range of Doctor Who short story anthologies. To date, his work has appeared in the majority of the Short Trips collections. He has also edited three volumes in the series, The History of Christmas, Time Signature and How The Doctor Changed My Life. The second of these takes as its starting-point Guerrier's short story An Overture Too Early in The Muses. The third anthology featured stories entirely by previously unpublished writers. After contributing two stories to the anthology Life During Wartime in Big Finish's Bernice Summerfield range of books and audio dramas, Guerrier was invited to edit the subsequent year's short story collection, A Life Worth Living, and the novella collection Parallel Lives. After contributing two audio dramas to the series, Guerrier became the producer of the Bernice Summerfield range of plays and books, a post he held between January 2006 and June 2007. His other Doctor Who work includes the audio dramas, The Settling and The Judgement of Isskar, in Big Finish's Doctor Who audio range, three Companion Chronicles and a contribution to the UNIT spinoff series. He has also written a play in Big Finish's Sapphire and Steel range. Guerrier's work is characterised by character-driven humour and by an interest in unifying the continuity of the various Big Finish ranges through multiple references and reappearances of characters. As editor he has been a strong promoter of the work of various script writers from the Seventh Doctor era of the Doctor Who television series

Jacqueline Rayner is a best selling British author, best known for her work with the licensed fiction based on the long-running British science fiction television series Doctor Who. Her first professional writing credit came when she adapted Paul Cornell's Virgin New Adventure novel Oh No It Isn't! for the audio format, the first release by Big Finish. (The novel featured the character of Bernice Summerfield and was part of a spin-off series from Doctor Who.) She went on to do five of the six Bernice Summerfield audio adaptations and further work for Big Finish before going to work for BBC Books on their Doctor Who lines. Her first novels came in 2001, with the Eighth Doctor Adventures novel EarthWorld for BBC Books and the Bernice Summerfield novel The Squire's Crystal for Big Finish. Rayner has written several other Doctor Who spin-offs and was also for a period the executive producer for the BBC on the Big Finish range of Doctor Who audio dramas. She has also contributed to the audio range as a writer. In all, her Doctor Who and related work (Bernice Summerfield stories), consists of five novels, a number of short stories and four original audio plays. Rayner has edited several anthologies of Doctor Who short stories, mainly for Big Finish, and done work for Doctor Who Magazine. Beyond Doctor Who, her work includes the children's television tie-in book Horses Like Blaze. With the start of the new television series of Doctor Who in 2005 and a shift in the BBC's Doctor Who related book output, Rayner has become, along with Justin Richards and Stephen Cole, one of the regular authors of the BBC's New Series Adventures. She has also abridged several of the books to be made into audiobooks. She was also a member of Doctor Who Magazine's original Time Team.

Colin Baker (born 8 June 1943, London) is a British actor who is known for playing Paul Merroney in The Brothers from 1974 to 1976 and as the sixth incarnation of the Doctor in the long-running science fiction television series Doctor Who, from 1984 to 1986. Colin Baker was born in London, but moved north to Rochdale with his family early in his life. He was educated at St Bede's College, Manchester and originally studied to become a solicitor. At the age of 23, Baker changed professions and enrolled at the London Academy of Music and Dramatic Art (LAMDA), where he studied alongside David Suchet.

George Mann is an author and editor, primarily in genre fiction. He was born in Darlington, County Durham in 1978. A former editor of Outland, Mann is the author of The Human Abstract, and more recently The Affinity Bridge and The Osiris Ritual in his Newbury and Hobbes detective series, set in an alternate Britain, and Ghosts of Manhattan, set in the same universe some decades later. He wrote the Time Hunter novella "The Severed Man", and co-wrote the series finale, Child of Time. He has also written numerous short stories, plus Doctor Who and Sherlock Holmes audiobooks for Big Finish Productions. He has edited a number of anthologies including The Solaris Book of New Science Fiction, The Solaris Book of New Fantasy and a retrospective collection of Sexton Blake stories, Sexton Blake, Detective, with an introduction by Michael Moorcock.

Matthew Waterhouse played companion Adric, a companion of Tom Baker and Peter Davison's Doctors from 1980 to 1982, in Doctor Who from Full Circle to Earthshock, with cameo appearances in Time-Flight and The Caves of Androzani. After leaving the series, he began a stage career. Waterhouse began his career as a clerk in the BBC news department before securing a role in the television drama To Serve Them All My Days in 1980. Shortly afterward he auditioned for and won the role of Adric. He was a confirmed Doctor Who fan and had had at least one letter printed in Doctor Who Weekly before he took up the role. Between 1998 and 2016 Waterhouse lived in Connecticut in the United States, though he regularly visited the UK. He has since returned to live full-time in the UK alongside his American husband, Tim. In 2010, Waterhouse joined a growing number of Doctor Who actors in publishing an autobiography. In his book, Blue Box Boy, he writes candidly about his experiences making Doctor Who. Waterhouse also appeared in the 2019 documentary A Weekend with Waterhouse that appeared on the Doctor Who: Season 18 Blu-Ray release. Since 2014, Waterhouse has been reprising his role as Adric in Doctor Who audio dramas produced by Big Finish Productions. He has also written two novels for the company's range of Audio Novels based on the series, the most recent being Prisoners of London, released in July 2023.