Nicholas Briggs is a British actor and writer, predominantly associated with the BBC science fiction television series Doctor Who and its various spin-offs. Some of Briggs' earliest Doctor Who-related work was as host of The Myth Makers, a series of made-for-video documentaries produced in the 1980s and 1990s by Reeltime Pictures in which Briggs interviews many of the actors and writers involved in the series. When Reeltime expanded into producing original dramas, Briggs wrote some stories and acted in others, beginning with War Time, the first unofficial Doctor Who spin-off, and Myth Runner, a parody of Blade Runner showcasing bloopers from the Myth Makers series built around a loose storyline featuring Briggs as a down on his luck private detective in the near future. He wrote and appeared in several made-for-video dramas by BBV, including the third of the Stranger stories, In Memory Alone opposite former Doctor Who stars Colin Baker and Nicola Bryant. He also wrote and appeared in a non-Stranger BBV production called The Airzone Solution (1993) and directed a documentary film, Stranger than Fiction (1994). Briggs has directed many of the Big Finish Productions audio plays, and has provided Dalek, Cybermen, and other alien voices in several of those as well. He has also written and directed the Dalek Empire and Cyberman audio plays for Big Finish. In 2006, Briggs took over from Gary Russell as executive producer of the Big Finish Doctor Who audio range. Briggs co-wrote a Doctor Who book called The Dalek Survival Guide. Since Doctor Who returned to television in 2005, Briggs has provided the voices for several monsters, most notably the Daleks and the Cybermen. Briggs also voiced the Nestene Consciousness in the 2005 episode "Rose", and recorded a voice for the Jagrafess in the 2005 episode "The Long Game"; however, this was not used in the final episode because it was too similar to the voice of the Nestene Consciousness. He also provided the voices for the Judoon in both the 2007 and 2008 series. On 9 July 2009, Briggs made his first appearance in the Doctor Who spin-off Torchwood in the serial Children of Earth, playing Deputy Prime Minister and Foreign Secretary Rick Yates.

David Llewellyn is a Welsh novelist and script writer. He grew up in Pontypool and graduated from Dartington College of Arts in 2000. His first novel, Eleven, was published by Seren Press in 2006. His second, Trace Memory, a spin-off from the BBC drama series Torchwood, was published in March 2008. Everything Is Sinister was published by Seren in May 2008. He has written two novels for the Doctor Who New Series Adventures: The Taking of Chelsea 426, featuring the Tenth Doctor, and Night of the Humans, featuring the Eleventh Doctor and Amy Pond. In addition to writing novels, Llewellyn wrote the Bernice Summerfield audio play Paradise Frost and the Dark Shadows audio drama The Last Stop for Big Finish Productions. Llewellyn lives in Cardiff.