Joe must investigate Andy, a fellow FBI handler who's also one of his best friends, after a city councilwoman is murdered and the chief suspect is an informant under Andy's direction.
Darnell and Heather go undercover to infiltrate a band of bank robbers making its way across the U.S.; Lily poses as a waitress to get the goods on a dirty judge in a case that gets personal for Joe.
Joe and Heather work a sting involving an accused corporate raider who has hired them to take out one co-workers. Lily and Darnell pose as a book dealer and supplier to take down a forger trying to pass off fake manuscripts as real.
Lily goes undercover as an Irish nanny to determine the whereabouts of another Irish nanny who has gone missing and is maybe dead. Joe tries to set Darnell up as a collector/enforcer for a high-powered bookie they want to bring down.
Joe and his crew pose as filmmakers involved in the adult-movie industry to lure a porn-obsessed man suspected of murdering his wife for insurance money. Also, an acquaintance asks Joe to help find her missing 14-year-old sister.
Lily is undercover as young Irish mobster's girlfriend. She agrees to marriage to draw his mob boss father into position for arrest. Joe orchestrates wedding as bait, but Lily has to go through with it and marry the guy to get their man.
Elena enters a rehab clinic in order to find out where $5 million in missing DEA money is located; Darnell poses as a hit man to thwart a murder attempt, in a case involving a nationwide drug ring.
Joe and team infiltrate dating service to catch woman suspected of killing past dates. Caroline Glenwood is the lethal temptress. Joe, poses as potential suitor, his crew as dating service employees to stop her before she kills again.
An FBI agent trains and handles agents who go under cover to solve crimes; Joe mourns the loss of one of his own as the dangers of the job become all too real.