It's time the truth was told. About UNIT. About the Cybermen invasion. About the so-called `Doctor'. About what happened all those years ago, at Warlock's Cross.About the man they keep locked up in a cage, in a secret prison.It's time. Because UNIT scientific adviser Elizabeth Klein is going to help ensure the truth is brought to light.Today's the day that UNIT falls.Big Finish have been producing Doctor Who audios since 1999, starring Tom Baker, Peter Davison, Colin Baker, Sylvester McCoy, Paul McGann, David Tennant and John Hurt.The Doctor in this story is played by Sylvester McCoy, familiar to many viewers and audiences not only as the Doctor, but most recently as Radagast the Brown in Peter Jackson's blockbusting The Hobbitmovie trilogy!Guest actor Tracey Childs is known to TV audiences for roles in Howard's Way, Hollyoaks, Broadchurchand Doctor Who, but to fans of Big Finish's Doctor Who stories her recurring Klein character first debuted opposite a certain David Tennant in the adventure Doctor Who - Colditz.CAST: Sylvester McCoy (The Doctor), Tracey Childs (Klein), Blake Harrison (Daniel Hopkins), Genevieve Gaunt (Linda Maxwell), Richard Gibson (Colonel McKenna),Tom Milligan (Gregory Lord), Russ Bain (Lieutenant Colonel Lewis Price).