Despite a decent effort from Louis Hayward as visiting Scotland Yard Inspector "Grayson", this is still a pretty clunky, charm-free, cold war espionage story that sees him team up with FBI counterpart "O'Hara" (Dennis O'Keefe) to investigate the smuggling of top secret formulae from a government facility to an enemy.... Their method of transferring the information is quite clever, but neither the script, nor the rather over-powering Reed Hadley narration really get this going. It has an almost documentary feel to it; the scenes are stitched together rather than fluid, and it comes across almost like a public information film about being beware of traitors in our midst (I found the culprit to be pretty obvious from the get-go), rather than to create any meaningful sense of suspense or drama. It has many of the usual set-piece cloak and dagger scenarios, and as ever with these type of stories - the baddies seem always unable to push home their obvious advantages! It's not dreadful, just procedural and rather dull.