5E. The Power Of Kroll

Season Sixteen - 1978/1979 (The Key To Time)

Script Editor: Anthony Read
Writer: Robert Holmes
Produced by: Graham Williams
Director: Norman Stewart
Designer: Don Giles
Incidental Music: Dudley Simpson


The trail for the Key To Time leads the TARDIS to Delta Magna's third moon. The Doctor and Romana get caught in a feud between the native Swampies and a group of Methane refiners.

Niether side take to the newcomers, and Romana is very nearly sacrificed by the Swampies to their God, Kroll. The Swampies are being armed by a gun smuggler Rohm Dutt. It is supposed that he is doing it on behalf of the Sons of Earth.

Dutt has in fact been hired by Thawn, one of the refinery workers. The idea was to have the armed swampies provoked into an attack, thereby any killing of the Swampies would be justified.

The Doctor discovers that Kroll is not in fact a God, but is very large giant squid. Apart from just being a giant squid, it is also the fifth segment of the Key to Time.

Regular Cast

  • Voice of K-9: John Leeson
  • Romana: Mary Tamm

Guest Cast

  • Thawn: Neil McCarthy
  • Ranquin: John Abineri
  • Fenner: Philip Madoc
  • Skart: Frank Jarvis
  • Dugeen: John Leeson
  • Varlik: Carl Rigg
  • Rohm Dutt: Glyn Owen (1-3)
  • Harg: Grahame Millard (1,2+reprise 3)
  • Mensch: Terry Walsh (1-2)
  • Swampie Walk-Ons: (all 1) Philip Bird, Curtis Dabek, Richard Edmunds, Mark Hardy
  • Swampie Extras: (all 1-2) Michael Atherton, David Babin, Graham Baker, Norman Clive-Fisher, Peter Crutchley, John Hodges, Paul Mann, Julian Mark, Steve Palmer, Steven Pleasance, Steve Sandis, David Sinclair, Paul Smith, Barry Stearn, Steve Vickers, Mike Wilson
  • Stuntman: Terry Walsh (2-3)

Original broadcast on the BBC

Channel Title Date Viewers Rating
BBC 1 496. Part One Saturday, December 23, 1978 6:15 PM - 6:40 PM 6.5M
BBC 1 497. Part Two Saturday, December 30, 1978 6:30 PM - 6:55 PM 12.4M
BBC 1 498. Part Three Saturday, January 6, 1979 6:25 PM - 6:50 PM 8.9M
BBC 1 499. Part Four Saturday, January 13, 1979 6:25 PM - 6:50 PM 9.9M 63%


  • Television Centre Studio 6

Outside Locations

  • Boat landing at the Maltings, Snape, Suffolk
  • Iken Cliff, Suffolk
  • The Wetlands, River Alde, Suffolk

Working Titles

The Shield of Time

The Horror of the Swamp


K-9 does not appear in the story; John Leeson actually appears as Dugeen.