Undercover ATF and DEA Agents are reminded to never judge a book by its cover and to always be on their toes; even small-time suspects have the potential to unleash terror, and no place seems safe or off-limits.

ATF undercover agent Dominick Polifrone aims to pass himself off as a mobster to stop the Iceman serial killer; Bergen County undercover detective Carlos James poses as a gang member to disrupt a treacherous plot against a woman's ex.

In the cities of Daytona and Cocoa, ATF Special Agent Perala's life is threatened when suspects turn the tables on him; in New York, a tipster claims that a man awaiting trial is planning an attack on his alleged rape victim before she can testify.

ATF Special Agents Dobyns and Kilday put their best feet forward only to have their lives put on the line.

An undercover NYPD officer and an ATF special agent learn not to trust a suspect's demeanor; forced to rely on their cover teams for support, Shaulene Wright and Scott Perala navigate the challenging terrain of deception in the undercover world.

Undercover agents Lyle Kirian and Brian Townsend embed themselves in two different, but equally dangerous worlds in order to investigate suspected local gang members and the Mexican cartel.