Even with her slow recovery, Mary's determination to track down the bastard who shot her gives her a boost.

Back in 2003 when Mary met Marshall for the first time, they were both attempting to get lovers Claudia Tobin and Henry Doer into a WitSec program. However, it's confusing if it's Claudia and Henry's relationship or Mary and Marshall's relationship that's going to last.

After being left for dead and being in a coma for three years, ATF agent Wade Guthrie comes back after being shot byballoon trader Jasper Malone to find out how the world has changed since he left.

An FBI informant who refuses WITSEC protection, and gets in serious trouble. Stan works with a witness who is "punch drunk", suffering from pugilistic dementia.

Mary's witness Dominic, a former hit man with a fondness for explosives, falls in love for the first time. But when things go awry, Mary races to stop him from returning to his old profession to seek revenge against his girlfriend.

Mary's assignment is to help a parolee acclimate to life outside of prison, and Marshall helps out when one of Mary's witnesses becomes the victim of a revenge plot.

FBI Agent Mike Faber returns with a new witness for Mary, who was involved in a mortgage-fraud scheme, and an ulterior motive.

Marshall deals with feelings of inadequacy when his dad, who is also a Marshal, comes Albuquerque to round up fugitives with outstanding warrants. Elsewhere, Brandi returns home with an odd explanation for her disappearance, and a guest in tow.

A woman wants to escape from her family, who is heavily involved in organized crime, but a secret from her past puts her eligibility for the Witness Protection program in jeopardy.

A witness with Asperger's Syndrome refuses to testify against her friend, frustrating Mary. Elsewhere, Marshall and Stan try to prevent the deportation of a key witness; and Brandi comes clean about her investment plan with Scott.

Mary's newest witness is a homeless man who exposed a pipe bomb plot. As he struggles to conform to the rules of WitSec, Mary agrees to help him search for his birth parents – which presents unexpected problems when they are found. Meanwhile, Brandi becomes distrustful of Scott who once again needs money.

Mary plays "stepmother" to a rebellious 16 year-old witness of a jewelry heist whose separated parents are too self-involved to deal with their teenaged daughter's issues. Meanwhile, Marshall suspects that a witness has sold out his brother at a family reunion. Plus, Brandi takes care of Scott after he is assaulted under mysterious circumstances.

A priest, who witnesses the cuddle of a stripper, is all too eager to leave the priesthood when he joins Witsec but hesitant to cut off ties with the victim's family. Stan struggles with telling a deceased witness's daughter the truth about her delinquent father. Brandi decides to move in with Peter while Jinx returns and offers Mary motherly advice on dating.