Guest Stars Helen Shingler as Mme. Maigret Neville Jason as Lapointe Anthony Jacobs as Joseph Noel Howlett as Comeliau Carl Duering as Victor Gwen Cherrell as Louise Eddie Malin as Locksmith Sheila Robins as Martine Pauline Letts as Madame Fumal Eric Pohlmann as Fumal Derek Benfield as Emile David Courtney as Felix Cicely Paget-Bowman as Madame Gaillardin Uncredited John Hart as Character in Corridor
