A group of criminals raid an important British atomic laboratory and photograph some key documents onto microfilm. When the customs officers quickly clamp down on passengers leaving the country, one of the men hides the film in the mink coat of the ventriloquist performer Penny Page who is flying to Paris. When Brady's sister Diane witnesses this, the pair find themselves drawn into a deadly game as the criminals try to get the invaluable film back from Mrs Page.

When the reformed career criminal is framed for an armed robbery and sent to prison again, he is determined to get free and prove his innocence and escapes 5 times before being recaptured. Curious about the story, Brady decides to investigate and helps the man to escape again to discover the truth behind the conviction...

When one of Brady's colleagues announces that he will not be returning from his holiday in Italy, and is seen using his mathematical talents to win at roulette, Brady decides to fly out and convince him to return - but he soon discovers that Professor Owens is working to save his daughter who is being held hostage by the mob...