Joe and his agents infiltrate a dating service in order to catch a woman who is suspected of killing several of her past dates. Caroline Glenwood is a lethal temptress, suspected of murdering more than one of the wealthy men she has met through dating services. Joe, posing as a potential suitor, puts his crew in place posing as dating service employees in order to stop Glenwood before she kills again.
Lily is undercover as the girlfriend of a young Irish mobster. She ends up agreeing to marry him in order to draw his mob boss father into a position to be arrested. Joe orchestrates the wedding as bait but it turns out Lily has to go through with it and marry the guy in order for them to get their man.
When Joe and Heather work a sting operation involving an accused corporate raider they find out that he hired them to take a hit out on one of his fugitive co-workers. Meanwhile, Lily and Darnell pose as a book dealer's and a supplier in order to take down a forger who has been trying to pass off fake manuscripts as the real thing.
Joe handles a ""black op"" for his FBI boss investigating the death of an FBI agent working undercover with the LAPD, investigating them for brutality under cover of the law. Darnell poses as a reporter, Lily as a medical student in the autopsy, and even Marcy returns to UC work as a funeral director.
Artie, Joe's friend, comes back into town, and offers Joe a business proposition. His plan is to dig a tunnel from a bookstore to the bank across the street right into the vault. Lily goes undercover as the bookstore owner to keep the customers distracted from what's going on in the basement with Joe and Bruno. Also, things get complicated when Joe's old flame shows up and wants to move in with him.