The gist of this story is settled pretty quickly as a secret sonic device is pinched by “Sven” (Anthony Dawson) and “Helga” (Mary Laura Wood) the wife of it’s inventor from their Stockholm home. Off they set across country, making for Finland and then the USSR. Hot on their tails are intrepid detective “Peterson” (Jack Warner) and the scientist “Ahlen” (John McCallum) who are both determined to stop them before they can sell the gadget to the Soviets. The espionage elements of this are all relatively plain sailing, but the photography of the Arctic wilderness as they give chase is what really makes this worth a gander. There are reindeer by the hundreds being herded by the locals; their lives free of technology and their innate friendliness meaning that these folks look after all comers. Just as that helps those pursuing, it helped those fleeing too. It all culminates in a pristine valley where the snow clings, precariously, to the sides of the mountains ensuring that the local population use only eagles to hunt - silence isn’t so much golden as essential. Can the chasing pair catch up with their antagonists in time? Warner really only ever had one gear, and he doesn’t challenge himself (or us) with his characterisation here. Dawson delivers competently as he usually does when he is the baddie, and the others contribute adequately, if maybe just a bit too verbosely, as the adventure slowly advances amidst the snow and ice to a denouement that is just a little different. It’s nothing special, this film, but I thought the last ten minutes just about made it worth the watch - and, yes, there are a few eagles, too.