Matt Flannery and Emily Lehman are the top-ranked negotiators in the FBI's Crisis Negotiation Unit (CNU). They're experts in their field -- and they also happen to be sleeping with each other, a secret that Matt accidentally reveals to the world during a hostage standoff. The revelation causes friction between Matt -- who relies on gut instinct -- and the more analytical Emily. It also draws the ire of boss Cheryl Carrera, head of the Los Angeles CNU. While Matt and Emily should be split up for being romantically involved, they're way too valuable as a team.