Hayward is a clichéd stereotype--the tough as nails lady who really just needs a man! Because of this, you KNOW where the film will eventually go. If you think about it, this is the sort of woman she ALSO played in "The Conquerer", "Where Love Has Gone", "David and Bathsheba" and countless other films.
The movie begins with a VERY one-dimensional lady publisher (Hayward) deciding to do a hatchet piece on a famous general. In other words, while she would pretend to be fair, she already decided to make the article very negative regardless of how their interviews go. So, she invites him over to her house to stay for a few days--and again and again, she tries to trip him up and get him to say something she could twist and take out of context. As for the General (Kirk Douglas), he's almost as one-dimensional--way too perfect, sexist and in control to be real. I am surprised after this inauspicious beginning that I actually continued watching the film--especially since I knew what would happen next. After all, the fact that the movie is called "Top Secret Affair" made this deduction pretty easy! Basically, she tries again and again and again (without luck) and in the process falls in love with the guy. Is there more to the film than this? Not really.
Considering that at the time, Douglas and Hayward were top stars, it is surprising they'd be put into such a mediocre B-movie plot. Despite the budget, it's not a particularly good film and it's not surprising that the film isn't particularly famous. A must-see for die-hard fans of Douglas or Hayward but no one else.
By the way, I read one time that Kirk Douglas didn't like folks knowing he was 5'9" (which, by the way, is a perfectly fine height). In many films, they either hired very short actors or put them in trenches to make him appear taller. In the film, he even says he's 6' tall!