AllMovie

The Third Secret is a brooding, atmospheric mystery tale that deserves greater exposure, especially for fans of the detective film. Not quite film noir, it does share some of the visual features associated with that genre, notably its moody, brooding black-and-white photography that sometimes seems to act as a character all by itself. Robert L. Joseph's literate screenplay is sometimes confusing -- possibly because at least one entire strand was edited out before the film's release -- but almost all of the pieces fit together, and it features a good share of memorable, characterful dialogue. While some will perhaps guess the identity of the killer too early, the script still builds to a satisfying and somewhat harrowing climax. Stephen Boyd is very good as the American journalist investigating the affair; his performance is thoughtful and well observed. Even better is Pamela Franklin, who rises to the challenges her part calls for and turns in one of the better children's performances of the time. The supporting cast is equally fine, with special mention going to Richard Attenborough's finely detailed portrayal. Charles Crichton has directed with admirable restraint without sacrificing force and effect. Sharp-eyed viewers will catch Judi Dench in her film debut.