After being discharged from the hospital with a fresh bullet wound scar, Mary gets right back to work with Marshall. They come across what appears to be video footage of an armed robbery that one of their witnesses used to orchestrate as a mobster in Boston. The witness: Jimmy Mc Cabe. After grilling Mc Cabe, Mary turns her attention to Jimmy's sons who are doing their best to conceal the truth about their dad. Meanwhile, Marshall's presence in gangland is starting to hurt gang-banger Lala's business. But Marshall is looking for the name of Mary's shooter. It's only a matter of time before Lala's proximity to the cops ruins his business, & before Marshall gets in too deep. ...

Judy Wagrowski (Karina Logue) is not your average accountant. She was once hired to keep track of the earnings in an illegal numbers racket in Pittsburgh, PA. After being raided by the feds, Wagrowski was turned over to Wit Sec & Mary becomes frustrated while trying to adjust to Judy’s condition. Unable to lie & struggling with body language, Judy is given a job as an accountant’s assistant while she waits to testify in the federal case. Mary walks a fine line as she instructs Judy to lie about her identity while in witness protection but to tell the truth in the courtroom once she’s called upon to testify against her former boss, Larry Silvers (David Barrera). Marshall & Stan have their hands full as well when a current Wit Sec case becomes worried about her status as an immigrant in the States. Stan puts the pressure on the I.C.E. to renew her status, but he finds out that she may be involved in criminal activity. ...

Wit Sec receives a homeless but genius man who witnessed a homegrown bomb attempt & called the authorities, saving hundreds of innocent people. Walter Cooper (Esteban Powell) once lived off the streets of Seattle Washington & consumed the many books at the library he lived in. But now, Mary & Marshall have to clean up this federal witness to that he’s a credible witness for the U.S. Attorney’s case. After cleaning up, Walter starts a job at a local Albuquerque bookstore where he’s anything but receptive to the idea of an alarm clock, schedule, uniform & nametag. When Wit Sec uses a federal databank to track down a wanted local fugitive on the FBI’s top ten list, Walter gets the idea to use the same method to find his birth mother. Adopted at a young age, Marshall & Mary find out where Walter’s mother is located but must race against time to reconnect the two after they find out that she’s in grave trouble. ...

A teenager witnesses a bloody diamond store heist & she is immediately introduced into Wit Sec protection. However, her mother stays behind & lets her father accompany her. Mary takes the reigns & finds that Sabrina (Spencer Locke), the daughter, is torn between her separated parents who dislike one another. Her mother (Jessica Tuck) barely has any time to see her on planned visitations in Chicago, & her father (Christopher Cousins) thinks he can buy her love with cars & gifts. Mary is left to emotionally guide her as the "stepmother" & make sure that Sabrina makes her federal hearing to testify against the criminals. Meanwhile, Scott’s gambling debts have caught up with him. He ends up in the hospital, badly beaten. He claims that he was mugged & robbed, but Brandi is beginning to think there are other factors at play. ...

Mary & Marshall's first case together in 2003 is revisited after an amorous couple in Baltimore witnesses the brutal killings of the boyfriend's family. Marshall & a reluctant Mary must transport Henry Doer (Josh Cooke) & Claudia Tobin (Jeannine Kaspar) across the country to the safe haven of Albuquerque. Flash-forward to 2010: Mary & Marshall are rehashing this first case when the couple
- now on the road to romantic ruin
- jeopardises their identities when Henry comes to realise that the romance has died. There's also a new face at Wit Sec headquarters. The newly appointed U.S. Marshall in town Allison Pearson (Allison Janney), doesn't make a very good first impression with Mary. Mary's sister, Brandi (Nichole Hiltz), is struggling to have her tuition check refunded. & Peter even offers to help her financially, but Brandi has plans of her own.

...

An ATF agent is gunned down when an arms deal goes bad in El Paso, Texas. After awaking from a coma three years later, Wade Guthrie (Mike Doyle) is placed under Wit Sec protection as a star witness in a federal case. Wade's longing to be reunited with his past girlfriend leads Wit Sec into a dilemma as his partner & former girlfriend are now much more "acquainted." When Wade breaks free of US Marshal custody in order to see his former girlfriend, Mary & Marshall go into damage control mode & try to pacify an explosive situation. Also, Marshall relies on fate to link himself with a beautiful pharmaceutical saleswoman named Breck. Could this be love or just a flash in the pants? Meanwhile, Mary juggles the arrival of her fiancée's aunt, who is representing Raph's mother at the engagement party, & the new head at Wit Sec, Allison Person, who is making life difficult for Mary. ...

The FBI & Wit Sec are working together to protect a whistle-blower & it appears Mary has met her match. Mary & Special Agent Mike Faber (Steven Weber) butt heads when she arrives. She also finds out that Earl Donaldson (Geoffrey Blake) hasn't been told about all of his witness possibilities. When Donaldson finally chooses to enter witness protection, he jeopardises his family's safety by telling them about his choice in a bugged house. The FBI's money laundering case then turns into a kidnapping investigation. Wit Sec & the FBI must race against time in the hopes of finding their witness who has actually taken matters into his own hands. Back in ABQ Stan Mc Queen (Paul Ben-Victor) is helping an ex-boxer who is experiencing dementia. His fighting days long behind him, Ricky Dumont (Chad Coleman) believes he's still a heavyweight & that Stan is his old trainer. ...

Mary & Marshall travel to Providence, RI to observer their witness' trial when Dominic Difazzio (Louis Lombardi) becomes a star witness against his uncle & mob boss, Vincent Difazzio (Roy Costley). Given Difazzio's murderous track record with explosives, he's not one of Mary's favourites. After settling into his new life in New Mexico, Difazzio opens a local fish store & falls in love with a business neighbour named Naomi (Salli Saffioti). The only problem is that he doesn't know how to act around women, having never been on a date. He begs Mary for a little advice, & she grudgingly agrees. Mary says her goodbyes to Raphael (Cristián de la Fuente), only to run into him later when she accompanies Difazzio on his first date. Difazzio's date goes swimmingly & he tells Mary that he thinks he sees wedding bells in his future. ...

Thirty-eight years ago, Frank Jergens' (Fred Ward) good side showed itself while he was robbing a bank. During the heist, he turned on the dirty cops who were helping him pull it off. After 38 years in the pen, Jergens is released to Mary & Wit Sec, but not before making friends & connections on the inside. Mary is very concerned about Frank's friend, Ray (Brian Goodman), who is indebted to two criminals who are eager to collect. & the more that Mary engages with Frank, the more she is reminded of her father. When Frank's friend Ray shows up at his door in dire straits, Frank must decide whether life on the outside is as good as it's cracked up to be. Meanwhile, Mary gets into trouble with Wit Sec administrators when they find out she's been abusing U.S. Marshal services to track down her sister. Marshall also has his hands full with an ex-writer who is falling apart with her life under protection. ...