What an absolute gem. The beginning is a tad convoluted, but the detective team/romantic duo of "Iris" and "Gilbert" is delightful, as is "Ms. Froy", who is unfortunately present in the film somewhat briefly. I did question the 'persuasion' of cricket loving "Charters" and "Caldicott", and Sir Alfred's intent with those two... bizarre... And I couldn't tolerate very much of their "Crook's Tour" feature before bailing on it. My rating is solely for this wonderful steam-engine spy-thriller. FIVE STARS.