The Zero Imperative (home video)

Synopsis
Former UNIT luminary Liz Shaw and her assistant Lou Bayliss are investigating a series of bizarre murders, all committed near a soon-to-be-closed psychiatric hospital.

When the hospital is unexpectedly reprieved by rich Industrialist Peter Russell, events seem to move out of Liz's control. Are the incumbent director of the clinic, Doctor Dove and his predecessor Doctor O'Kane, harbouring the killer? What is the centuries-old horror hidden in the grounds?

And what exactly is the secret of room zero?

Plot
to be added

Cast

 * Liz Shaw - Caroline John
 * Dr. Jeremiah O'Kane - Jon Pertwee
 * Dr. Colin Dove - Sylvester McCoy
 * Dr. Peter Russell - Colin Baker
 * Lou Bayliss - Linda Lusardi
 * Patient Zero (David O'Kane) - David Terence
 * Dr. William Bruffin - Mark Gatiss
 * Dr. Beatrice Hearst - Nicola Fulljames
 * Patricia Haggard - Louise Jameson
 * Dr. Gilchrist - Patricia Merrick
 * Cummings - Jonathan Rigby
 * P.R.O. - Sophie Aldred
 * Orderly - Simon Messingham
 * Orderly - Alexander Kirk
 * Daniel - Bill Baggs
 * Boy's Voice - Daniel Mills

Production crew

 * Executive producer - Andy Grant
 * Original Music - Mark Ayres
 * Cinematography - Dick Kursa
 * Film Editing - Michael Duxbury
 * Art Direction - David Rowston
 * Makeup artist - Sarah Dickinson
 * Assistant directors - Patricia Merrick, David Rowston, Edward Salt
 * Gaffer - David Hilton

Story notes

 * Gary Gillatt created the Nightshade video covers.
 * This film is the debut of the Preternatural Research Bureau (PROBE) and the return of Caroline John as Liz Shaw, a character last seen on television in DW: Inferno in 1970 (discounting a psychic projection of Shaw played by John that appeared in 1983's The Five Doctors).
 * Several cast members previous portrayed (other) roles in Doctor Who: Jon Pertwee (Third Doctor who acted along side Caroline John); Colin Baker (Sixth Doctor); Sylvester McCoy (Seventh Doctor); Sophie Aldred (Ace); and Louise Jameson (Leela).
 * Simon Messingham went on to write/had written: NA: Strange England EDA: The Face-Eater, The Infinity Race, PDA: Tomb of Valdemar and The Indestructible Man.
 * This is the first of four films featuring the PROBE organisation. It pre-dates Torchwood as the first ongoing spin-off of the Doctor Who universe.
 * The canonicity of this and the other PROBE storylines has never been officially confirmed. If it does fit within the Whoniverse, it marks the first time Pertwee, Aldred and Jameson have played more than one role in it. It is not the first time for Baker and McCoy, however: Baker played Maxil in DW: Arc of Infinity and McCoy briefly played the Sixth Doctor in DW: Time and the Rani.

Myths
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Filming Locations
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Discontinuity, Plot Holes, Errors
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Continuity

 * Liz Shaw last appeared on-screen in DW: Inferno, apart from a brief appearance as a psychic projection in DW: The Five Doctors. In spin-off media, she appeared with the Third Doctor several times chronologically afterward. (PDA: The Wages of Sin, The Devil Goblins from Neptune), and died in 2003 while on the Moon, (NA: Eternity Weeps) but she was still alive as of 2010 according to SJA: Death of the Doctor.

DVD, video, and Other releases
to be added