U.S. Marshal Mary Shannon has a relatively simple day ahead of her: Pick up federally-protected witness, Tasha Turischeva, and get her situated in her new living situation with the help of her partner, Marshall Mann; make sure her sorta-kinda boyfriend, Raphael, picks up her ne'er-do-well younger sister, Brandi, from the train station, and survive the "surprise" birthday party her man-crazy mother
Mary protects a 10-year-old witness from being returned to his father, one of the largest drug traffickers in the Midwest.
Mary must act as maid of honor to protect her witness - a diamond smuggler - at her high-profile wedding.
Mary and Marshall are caught in the cross-fire of a contract killer while transporting a witness who is particularly irritating.
Mary works to solve the mystery of who tried to kill her witness, an art dealer. To complicate matters, both his mistress and his wife are in the program, and key suspects.
Mary learns that her witness, a NCAA basketball star, has a gambling problem that could destroy his new life.
An entire family is forced to enter WITSEC after their teenaged daughter witnesses a gang shooting.
When Mary's witness seems to have died in a car accident, she thinks it may be related to his past life.