U.S. Marshal Mary Shannon works for the Federal Witness Protection Program (WITSEC) relocating and protecting career criminals, compulsive liars, thieves, murderers, and the occasional innocent bystander. With the help of her partner Marshall Mann (yes, Marshal Marshall) and her beat-up but beloved car, she just may get through her workday in time to deal with her sort-of boyfriend, her flaky sister, and her ne'er-do-well mother.