Serial 5E:
The Power Of Kroll


For the fifth segment of the Key To Time, the Doctor and Romana travel to the marsh moon of Delta Magna. There, the time travellers become enmeshed in tensions between the barbaric native Swampies, the gun-runner Rohm-Dutt, and the crew of a refinery which is trying to drive the Swampies away. In the midst of all this, the Swampie god, a gargantuan squid named Kroll, is beginning to stir, and even the Doctor will be defenseless in the wake of the destruction wrought by Kroll.


With all six adventures of Doctor Who's sixteenth season forming a story arc depicting the Doctor's quest for the Key To Time, script editor Anthony Read tried to nail down the line-up of stories at an early stage. Despite his efforts, however, by May 1978 two problems remained: no title was pencilled into the fifth slot, while it appeared that Ted Lewis would be unable to complete his scripts for “Shield Of Zarak”, intended to be the fourth serial. Consequently, Read turned to two authors who had already contributed to Season Sixteen -- Robert Holmes, who had penned The Ribos Operation, and David Fisher, writer of The Stones Of Blood.

On May 26th, both Holmes and Fisher were commissioned to provide their second serials of the year. Fisher's story, The Androids Of Tara, was now planned to be the season's penultimate adventure, while Holmes' offering, “Moon Of Death”, would replace “Shield Of Zarak”. Holmes was a Doctor Who veteran, and so Read was confident that he would be able to complete his scripts by the time director Michael Hayes was due to join the production. Read asked Holmes to incorporate a monster whose size was unsurpassed in the annals of Doctor Who. He also advised him to dampen the humour he usually injected into his Doctor Who scripts, as requested by Head of Drama Graeme McDonald.

Michael Hayes feared that it would be impossible to successfully realise Kroll on a Doctor Who budget

Unfortunately, these requirements -- together with the framework imposed by the Key To Time storyline -- meant that Holmes found writing “The Horror Of The Swamp” (as “Moon Of Death” had been renamed) to be an unsatisfying experience. No more impressed was Hayes, who feared that it would be impossible to successfully realise Kroll, Holmes' giant monster, on a Doctor Who budget. Fortunately, Fisher had already started to deliver his scripts for The Androids Of Tara by this point. In mid-June, producer Graham Williams agreed that The Androids Of Tara and “The Horror Of The Swamp” could switch places in both the production and broadcast schedules. The Androids Of Tara would now be made first, under Hayes' aegis, while “The Horror Of The Swamp” became Serial 5E.

The new director allocated to “The Horror Of The Swamp” was Norman Stewart, who had helmed another serial with intense effects requiremenets, Underworld, the year before. As the summer progressed, Holmes' scripts came to be known as The Power Of Kroll. (They may also have briefly been called “The Shield Of Time”, in accordance with a short-lived effort to unify all the Season Sixteen titles under the format “The [Something] Of Time”.) The setting was originally a moon of Gannymede, before the latter was rechristened Delta Magna.

Unfortunately, Stewart was forced to make a number of cast changes as Serial 5E's production dates loomed. He had originally approached Martin Jarvis to play Dugeen, but Jarvis dropped out of The Power Of Kroll in mid-August. Given the story's marshy setting, Holmes had avoided using K·9, and so it was decided that John Leeson -- who usually voiced the robot dog -- should be hired in Jarvis' place. This was formally approved on August 22nd.

Then, in early September, The Power Of Kroll lost another castmember when Alan Browning (who was to portray Fenner) fell ill. Stewart contacted Philip Madoc -- who had played several villainous roles in Doctor Who over the years -- but Madoc misunderstood Stewart, and thought he was being offered the more substantial part of Thawn. Madoc was therefore very disappointed to find himself consigned to a more minor role, and The Power Of Kroll proved to be his last involvement with Doctor Who.

By 1978, a typical four-part Doctor Who story was allocated two studio sessions and a week of location filming. For The Power Of Kroll, however, Stewart arranged to sacrifice one of his studio blocks in favour of an extra week on location. The first day of filming in Suffolk occurred on September 18th, at the Maltings in Snape, while the next day took cast and crew to Iken Cliff at Iken.

A water-resistant German product made the Swampies' skin green, but no one had ordered the solvent needed to remove it

September 19th was the first day to feature the Swampies, whose skin was made green using a German product selected by make-up artist Kezia Dewinne for its striking appearance on camera and its resistance to water. Unfortunately, Dewinne had neglected to order the special solvent needed to remove the make-up. As a result, once shooting had wrapped for the day, some of the actors had to be despatched to RAF Bentwaters at Woodbridge to take chemical showers, while the remainder had their skin scoured by hand at the hotel. Despite these efforts, many of the Swampie actors would sport a green tinge for weeks afterward.

This was not the only mishap to arise during the location shoot. Visual effects designer Tony Harding intended to achieve Kroll using a model which would be inserted into the filmed material via split-screen (with the model on the top of the frame and the location footage on the bottom). However, film cameraman Martin Patmore, acting on poor advice, elected not to expose the upper portion of the film. This meant that a hard line would appear in the completed effect, making the join between the model work and the location footage obvious.

To make matters worse, producer Graham Williams was taken badly ill around this time. For the next several weeks, Read and production unit manager John Nathan-Turner assumed many of Williams' duties. They were aided by Blake's 7 producer David Maloney, who had directed a number of Doctor Who adventures, most recently The Talons Of Weng-Chiang.

The remaining work at the Maltings was completed on September 20th and 21st. Part of the latter day was spent at Iken Cliff, which was also the venue for September 22nd and the whole of the next week, from the 25th to the 28th. Production then shifted to Studio 6 at BBC Television Centre, spanning October 9th to 11th. The first day concentrated on scenes in the refinery control centre and corridor, as well as the pump room. The remaining pump room material was completed on the 10th, alongside sequences in the silo and on the gantry. The final studio day involved the sets for the control centre and corridor again, as well as the Swampie temple. Work on The Power Of Kroll then wrapped up with two days of model filming at Bray Studios, on October 19th and 20th. Effects problems continued to plague the story, however, as Harding discovered that his model for the refinery could not be photographed from the correct angle due to problems with the tank facilities.

Despite the success of The Hitchhiker's Guide To The Galaxy, Douglas Adams agreed to become Doctor Who's script editor

Meanwhile, with just one serial left to be made as part of Doctor Who's sixteenth recording block, behind-the-scenes tensions had begun to mount. Mary Tamm had become disenchanted with her character development, but refused to officially confirm her status for Season Seventeen. Anthony Read, on the other hand, was unambiguous in his decision to leave Doctor Who after a year and a half to concentrate on his career as a novelist. As his replacement, Read suggested Douglas Adams, who had written The Pirate Planet earlier in Season Sixteen. Adams met with a convalescing Williams in October, and despite the burgeoning workload that the success of his radio play, The Hitchhiker's Guide To The Galaxy, had brought him, Adams instantly agreed to the appointment.

But the most tumultuous situation concerned Tom Baker. Whereas Baker had enjoyed an amicable working relationship with Williams' predecessor, Philip Hinchcliffe, the series star was less enamoured of his current producer. Baker felt that after five years on Doctor Who, he should have more say in the programme's creative direction, and had aired his grievances to McDonald and BBC1 Controller Bill Cotton around September. By October, Baker's demands had escalated to include approval on virtually every facet of the production, including scripts, directors and casting. McDonald considered moving Williams to another programme, but finally decided it was time to cut ties with Baker. He instructed Williams to fire his lead actor, but the producer informed him that this was unnecessary: Baker had already left him a note declaring his intention to quit Doctor Who...

  • Doctor Who: The Handbook: The Fourth Doctor by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing, ISBN 0 426 20369 8.
  • Doctor Who: The Seventies by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing, ISBN 1 85227 444 1.
  • Doctor Who Magazine #312, 9th January 2002, “Archive: The Power Of Kroll” by Andrew Pixley, Panini Publishing Ltd.
  • Doctor Who Magazine Special Edition #9, 22nd December 2004, “I'll Put You Together Again” by Andrew Pixley, Panini Publishing Ltd.
  • In·Vision #36, February 1992, “Production” edited by Justin Richards and Peter Anghelides, Cybermark Services.

Original Transmission
Episode 1
Date 23rd Dec 1978
Time 6.17pm
Duration 23'16"
Viewers (more) 6.5m (85th)
· BBC1 6.5m
Episode 2
Date 30th Dec 1978
Time 6.31pm
Duration 23'57"
Viewers (more) 12.4m (26th)
· BBC1 12.4m
Episode 3
Date 6th Jan 1979
Time 6.28pm
Duration 21'56"
Viewers (more) 8.9m (51st)
· BBC1 8.9m
Episode 4
Date 13th Jan 1979
Time 6.27pm
Duration 21'58"
Viewers (more) 9.9m (31st)
· BBC1 9.9m
Appreciation 63%

Doctor Who
Tom Baker
Mary Tamm
Neil McCarthy
John Abineri
Philip Madoc
Glyn Owen
Carl Rigg
Frank Jarvis
John Leeson
Grahame Mallard
Terry Walsh

Written 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
Don Giles

Working Titles
Moon Of Death
The Horror Of The Swamp
The Shield Of Time

Updated 21st October 2009