Tom Baker

The Doctor

Elisabeth Sladen

Sarah Jane Smith

Ian Marter

Harry Sullivan

Wendy Williams

Vira

Kenton Moore

Noah

Richardson Morgan

Rogin

John Gregg

Lycett

Christopher Masters

Libri

Stuart Fell

The Wirrn

Nick Hobbs

The Wirrn

Gladys Spencer

High Minister (voice)

Peter Tuddenham

Voices on Nerva (voice)

Robert Holmes

Writer

Rodney Bennett

Director

Philip Hinchcliffe

Producer

Robert Holmes

Script Editor

John Friedlander

Visual Effects

Sylvia James

Makeup Artist

Nigel Wright

Lighting Director

Dudley Simpson

Original Music Composer

Dick Mills

Special Sound Effects

Tony Oxley

Visual Effects

Barbara Kidd

Costume Design

Roger Murray-Leach

Production Design

Marion McDougall

Production Assistant

John Lloyd

Sound

George Gallaccio

Production Manager

Delia Derbyshire

Theme Song Performance