Jon Pertwee

The Doctor

Katy Manning

Jo Grant

Nicholas Courtney

Brigadier Lethbridge-Stewart

John Levene

Sergeant Benton

Richard Franklin

Captain Mike Yates

Stewart Bevan

Cliff Jones

Jerome Willis

Stevens

Tony Adams

Elgin

Ben Howard

Hinks

Mostyn Evans

Dai Evans

Talfryn Thomas

Dave

Roy Evans

Bert

Mitzi McKenzie

Nancy

Ray Handy

Milkman

John Scott Martin

Hughes

John Rolfe

Fell

John Dearth

BOSS (voice)

Richard Beale

Minister of Ecology

Jean Burgess

Cleaner

Brian Justice

Yates' Guard

Terry Walsh

Guard

Roy Skelton

James