Appointment in Prague: Two theses, on which Doctor Petrie has based his reputation, are revealed as forgeries. He has been sponsored by Karl Dickinson, scientific benefactor, and Sir Iain suspects both men of not being what they seem.
Regular Cast: Clifford Evans (Sir Iain Dalzell), Anthony Valentine (Philip West), Alexandra Bastedo (Diana Dalzell), Brian Peck (Culliford)
Guest Cast: Neil Stacy, Geoffrey Toone, Maria Aitken, Denis Carey, Gordon Pitt, Steve Peters, Denzil Ellis, Martin Gordon, Elaine Ives-Cameron
Writer: Robert Barr / Director: Ronald Wilson
Original Airdate: 16 Jun 1970 on BBC One
Series: Codename Season 1 Episode 11