Doctor Who Concordance Wiki

"The Power of Kroll" is the fifth story of the sixteenth season of Doctor Who.


Part One[]

Part Two[]

Part Three[]

Part Four[]

Background information[]

  • Robert Holmes was commissioned on Friday 26th May 1978 to write a four-part story, entitled "Moon of Death" with two restrictions placed upon him. The script had to tie in with the Key to Time structure of the season and on the instruction of the production office, had to contain the biggest monster ever seen in Doctor Who. Holmes took his inspiration from the treatment of the native North American Indians by the European colonists, most notably the way indigenous peoples were forced into reservations while their homelands were exploited for natural resources.
  • Holmes' finished scripts - now titled "The Horror of the Swamp" - were delivered in early June 1978, only for director Michael Hayes to express reservations about realising Kroll on-screen after two weeks of pre-production. After discussing the matter with producer Graham Williams, it was decided to drop Robert Holmes' story into the fifth slot of the season and bring forward the originally-planned fifth story - "The Androids of Tara" - for Hayes to direct in the slot for the fourth story. A new director was appointed for "The Horror of the Swamp" - Norman Stewart, who joined the production in mid-July 1978. By early August 1978, the title of the story was changed yet again this time to "The Power of Kroll", which it would retain for transmission.
  • After the cast and crew had completed all the location filming for this story between Monday 18th and Friday 29th September, rehearsals for the studio recording took place between Monday 2nd and Sunday 8th October, 1978. These took place at the BBC's Acton rehearsal rooms in Ealing, London. The three-day studio recording session took place in Studio 6 at BBC Television Centre between Monday 9th and Wednesday 11th October 1978. Each day had two separate recording sessions. The first would be between 2.30pm and 5.15pm. The cast and crew would then break for a meal. Recording would recommence at 7.30pm and would continue until 10.00pm. The first day's studio recording revolved mainly around scenes set in the main refinery control centre. The second day was for scenes set in the other areas of the refinery - the pump room, rocket silo and gantry. The final day was for scenes set in the Swampie temple, plus the final scenes from the last episode set in the refinery control centre.
  • Although not mentioned in Robert Holmes's script, it was decided to give the Swampies a green skin. The use of green wetsuits was mooted, but, in the end, it was decided to apply green make-up to the actors' skin. The make-up was designed to be water resistant to stop it running on location but needed a special solvent to remove it from the actors' skin. It was only after filming for a day that it was discovered that the wrong solvent had been taken to the location. The Swampie actors had to be taken to the nearby RAF Bentwater at Woodbridge to have chemical showers to remove the dye, reportedly much to the amusement of the aircrews stationed there.
  • Dugeen originally measured the storm on the "Rochter" scale - it was changed to the "Diemster" scale in a late revision to the script.
  • Costume designer Colin Lavers gave the Swampies high-fitting loincloths, in attempt to make them appear to have longer than normal legs which he reasoned would be natural for a native species living in such conditions.

Links and references[]


  • Doctor Who - Tom Baker
  • Romana - Mary Tamm
  • Thawn - Neil McCarthy
  • Ranquin - John Abineri
  • Fenner - Philip Madoc
  • Rohm-Dutt - Glyn Owen
  • Varlik - Carl Rigg
  • Skart - Frank Jarvis
  • Dugeen - John Leeson
  • Harg - Grahame Mallard
  • Mensch - Terry Walsh

Uncredited performers[]

  • Michael Archer as a Swampie (1-2)
  • David Babin as a Swampie (1-2)
  • Graham Baker as a Swampie (1-2)
  • Philip Bird as a Swampie (1-4)
  • Norman Clive-Fisher as a Swampie (1-2)
  • Peter Crutchley as a Swampie (1-2)
  • Curtis Dabek as a Swampie (1-4)
  • Richard Edmunds as a Swampie (1-4)
  • Mark Hardy as a Swampie (1-4)
  • John Hodges as a Swampie (1-2)
  • Paul Mann as a Swampie (1-2)
  • Julian Mark as a Swampie (1-2)
  • Steve Palmer as a Swampie (1-4)
  • Steven Pleasance as a Swampie (1-2)
  • Steve Sandis as a Swampie (1-4)
  • David Sinclair as a Swampie (1-2)
  • Paul Smith as a Swampie (1-2)
  • Barry Stearn as a Swampie (1-2)
  • Steve Vickers as a Swampie (1-2)
  • Mike Wilson as a Swampie (1-2)


  • By Robert Holmes
  • Directed by Norman Stewart
  • Produced by Graham Williams
  • Production Assistant - Kate Nemet
  • Production Unit Manager - John Nathan-Turner
  • Incidental Music by Dudley Simpson
  • Special Sound - Dick Mills
  • Film Cameraman - Martin Patmore
  • Film Sound - Stan Nightingale
  • Film Editor - Michael Goldsmith
  • Studio Lighting - Warwick Fielding
  • Studio Sound - Richard Chubb
  • Visual Effects Designer - Tony Harding
  • Electronic Effects - Dave Jervis
  • Videotape Editor - Rod Waldron
  • Costume Designer - Colin Lavers
  • Make-up Artist - Kezia Dewinne
  • Script Editor - Anthony Read
  • Designer - Don Giles


23rd century; 25th century; 27th century; 2878

bacterium bioplast; bandolier; Bayeux Tapestry; the Baygule; Binaca Ananda; blood sacrifice; boat; burdock; butterfly; canoe; cellular regeneration; chief; cobalt; the Company; computer; creeper; dandelion; Delta Magna; depth charge; Diemster scale; director; drill fly; Dryfoot; Earth; egg; electrical storm; Elvedon Port; enzyme recycler; freighter; funicular gas separator; giant squid; Gothic Perpendicular; Great Book; gun; gunrunning; Hajes; hammer; high priest; hovercraft; hydrogen peroxide; jellyfish; K-9; Key to Time; knife; Kroll; little green men; Lytteker micro; Melba, Nellie; methane; methane catalysing refinery; mineralogical survey; moon; Mother Earth; Nual; orbit shot; oxygen; People of the Lakes; plasmin catalyst; police; pressure detonator; probe; protein; radar; radiation; rifle; rocket; Samoa; scanner; Seven Holy Rituals; Sons of Earth; spaceship; spear; Stelson; Stone of Blood; strawberry jam; Suite No. 2 in B minor; swamp glider; Swampie; Symbol of Power; the Tracer; vegetarian; wine glass