Mark Gatiss

Ted Gilbert

NSA

Frank Parris / Oscar Berlin, Parris / Berlin

NSA

Larry Grayson

Parris / Berlin

Donald

The Man

John Churchill, Lord Marlborough, Lord Marlborough

Various Characters

The Captain

Narrator

Prince Regent

Billy Matlock

Colonel Theakes

Mycroft Holmes

Dettweiler

Malcolm McLaren

Dr. Quentin Questa (voice)

Stephen Gardiner

Callum

Presenter

Tycho Nestoris

Cavor

Mycroft Holmes

Himself

Colonel Black

Self - Contestant

Rich

Hilary Briss / Mickey Michaels / Val Denton / Les McQueen / Lance Longthorne / Alvin Steele / Phil Proctor / Mrs Beasley / Mick McNamara / Neds / Lotte Lipp / Brian Morgan / Dr Chinnery / Iris Krell / Bobbin

Various Characters

The Captain, Gantok, Richard Lazarus

Kenyon

Peter

Radio Presenter With 'Spaceship' Theory / Wildlife voiceover (voice) (uncredited)

Jeremy

Hang Man Chang

Self

Himself

Agent

Rev Giles Shawcross

Self

Robert Louis Stevenson