It's easy to imagine “Hannay” (Robert Powell) regretting opening his door when “Scudder” (Sir John Mills), in flight, asks for refuge in his home. Soon, he's being told stories of international spying, murder, and deceit, and before long, “Hannay” is on a train toward the highlands with both police officers and some dangerous individuals pursuing him. Fortunately, he’s clever, so when he unexpectedly finds himself near a grouse shoot at an impressive estate, he makes friends with “Alex” (Karen Dotrice) and “David” (Miles Anderson). A distraction during the local Liberal election campaign leads to a frantic return to London where he must warn “Insp. Lomas” (Eric Porter) about the risks presented by the “39 Steps”, “Ariadne’s Thread,” and a potential war in the Balkans. While I still believe Robert Donat's portrayal was superior (1935), Powell does a commendable job of keeping everything moving as he travels across the country, attempting to survive and uncover the truth. Porter and David Warner also provide noteworthy performances as this version of John Buchan’s story moves toward its final moments suspended from Big Ben. It is true that it has something of a television movie appearance, which does lessen the feeling of danger at times, but overall it's a well-told narrative that I found entertaining.

Source on TMDB