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. ...

Marshall packs his bags for a witness escort out of state, leaving Mary behind in Albuquerque with FBI agent Mike Faber (Steven Weber), who's in town with a federal witness in need of protection from the Russian mob. Natalie Vickers (Alexandra Lydon) was once a part of a mortgage scam in Los Angeles, but now she's under Mary & Faber's watch. Seemingly too nonchalant about entering Wit Sec, Natalie has apparently attracted her accomplice & boyfriend to Albuquerque where they continue to operate real estate fraud & get caught in the process. The sexual tension between Mary & Faber rises, as the two of them work closely to stop Natalie from indulging in her criminal past. When Mary realises that Natalie is doing it all for love, the boyfriend becomes a target of the FBI. Yet, Faber has another conflict to deal with, his superior officer in charge Ike Dennis. After being promoted, Ike doesn't gel any more with the lower ranks. ...

Mia Cusato’s (Laura San Giacomo) life turns upside down after she shoots & kills her own uncle (Michael Badalucco) who was attempting to "whack" her. But Cusato’s future in Wit Sec is imperiled after she reveals a condition she’s hidden from her family, a condition that may make her a questionable federal witness against her mob boss husb&. Cusato & Mary hit it off when Mary discovers that their lives aren’t so different from one another. Mary pulls all the stops to make sure that Cusato will remain protected while being interviewed by the attorney general in charge of the case. Marshall also has his hands full with a witness, Patrick (Travis Schuldt), who has been secretly been involved with his gay lover, Bob (Evan Gamble). Bob had relocated to Albuquerque after Patrick entered Wit Sec. Marshall must figure out a way to talk Bob into entering Wit Sec so that the two can live together. Jinx comes close to relapsing after Brandi reveals that she has a half-brother ...

On Stan's orders, Mary arrives at Peter's auto dealership to turn in her beloved-but-too-conspicuous Mustang & learns that newly-engaged Brandi has joined the sales team. She's a natural saleswoman, but her fledgling career & newfound confidence are soon jeopardised when six luxury cars go missing from the dealership, & Brandi's record puts her at the top of the Albuquerque PD's suspect list. To add insult to Grand Theft Auto, Peter's parents make it clear that they don't exactly trust their soon-to-be daughter-inlaw's intentions, & the tension is driving a wedge between Brandi & Peter. ...

Pregnant or not, Mary Shannon has never been very good at unwinding. Which is why, in an attempt to force relaxation on her, Stan & Marshall hatch a plan to get her out of town. With Oscar riding shotgun, Mary heads into the desert to deliver a message to one of Marshall's witnesses, a new age alpaca farmer who just might have some insight to offer into Mary's current situation. & with a file full of prospective adoptive parents & some tough decisions to make, Mary could certainly use a little guidance, even if she is reluctant to heed the advice of a New Mexico mystic. Or a dog. ...

When a decorated soldier witnesses his superiors selling arms to the enemy & steps forward to do the right thing, he soon finds himself out of the Army, shipped off to Albuquerque, & in the Witness Protection Programme. Like most witnesses, John & his wife Sue have some trouble coping with the changes, but unfortunately their problems run deeper than adjusting to life off the base: John is suffering from Post Traumatic Stress Disorder, & his psychological state is putting the case & the witnesses in jeopardy. ...

Mary proves it takes one to know one when she visits a mafia-mistress-turned-witness named Grace Haddik, & discovers what both Marshall & Stan missed: Grace is pregnant. Very pregnant. Now that Grace's bun in the oven is out in the open, Mary & Marshall must do their best to keep mother & baby safe. Which in Mary's case means posing as Grace's life partner & holding her hand through the birthing process. ...