Ray Milland is on good form in this cold war thriller. He's scientist "Fields" who is providing photography of secret formulae to his foreign paymasters. Is this voluntarily or is he being blackmailed? Well the next ninety minutes sees him illustrate quite a degree of personal conflict as he delivers more and more information to the enigmatic "Mr. Bleek" (Martin Gabel) whilst becoming increasingly disgusted with his own behaviour. He takes to heavy drinking but that isn't going to help him when one of his couriers is accidentally killed and the FBI find evidence of espionage. His paranoia is well founded as they start to put together a list of possible traitors - and he knows he is going to be on it. What makes this drama all the more tense is the complete lack of dialogue. Nope, not a word is spoken as Herschel Burke Gilbert's score is left to do all the heavy lifting, and it does it well. It helps develop senses of tension, frustration, fear and panic whilst Milland, and the frequent use of the telephone ringing, delivers quite a palpable sense of desperation as the drama unfolds. I can't stay I loved the denouement, but it's simplicity; the tautness of the direction and the uncertainty as to the culpability of the perpetrator all adds up to quite an intriguing watch.