While being transported to the United Nations, the crown jewels of the nation of Marnsburg are stolen by criminal Jena Cole. Cole plans to sell the jewels for $3 million, and the IMF's assignment is to get them back. The team's plan is to have Barney gain her confidence by posing as the former cellmate of Cole's late brother. Meanwhile, the rest of the team tries to convince Jena that the jewels she has stolen were actually imitations.
- Fake jewels and real jewels get traded around a couple of times in this heist plot featuring Barney as a safecracker with advanced technology, Jim as his bloodthirsty creditor, and Willie leaving the dirty work to others for a change and playing a staid bank representative from the jewels' home country. Lovely criminal Barbara McNair latches onto Barney to steal the jewels for her, intending to send him to his death after the job is completed, despite the flash of romance that sparks between them.