This was called Cloak without dagger in the UK and Operation Conspiracy in the US.Now which is the worst?The leading lady is Mary Mackenzie who is rather good.Sadly she died in a car crash when only 44.Leslie Dwyer plays for him the unfamiliar role of a detective.Late in life he would become a TV star.The film is very cheaply made and it shows.There is the old quota device of having all actors on camera so that they can speak their lines and there would be no need to edit the film and eliminates the necessity for any close ups.The film is a typical product of its era,particularly since it harks back to missed opportunities during the war.It is a fairly exceptional film that will not linger in your memory once the end title comes up.