The Marnsburg Crown Jewels were brought to the U.S. and stolen from the UN Building - Jena Cole, a thief, is believed responsible but have no leads on the location of the jewels. The IMF must recover the jewels before the hostile Marnsburg government makes a case out of it. Jena is to turn the jewels over to the Syndicate, which financed the theft. Barney manage to get close to Jena and she finds he has plans to the Marnsburg Consulate. Meanwhile, the IMF return the ""real"" jewels, claiming the first ones were fake and confirming it throuigh her diamond fence (a IMF replacement). Jena and Barney team up to get into the consulate and steal the ""real"" jewels and turns them over to Jim the creditor, so Jena tries to fake him out for substituting her supposedly fake gems for the ""real"" ones, then sneak out. The Syndicate shows up and figures out which gems are which, and the police take everyone, including Jena, into custody.

Barney s'infiltre dans une bande de malfrats qui viennent de voler les bijoux inestimables d'un petit pays européen. Jean Cole, la chef des truands, tombe follement amoureuse de l'agent.