Based on real events, the story follows a father and son (Offerman and Tremblay) who identify as Sovereign Citizens, a group of anti-government extremists, as they venture across the country and find themselves in a standoff with a chief of police (Dennis Quaid) that sets off an intense manhunt with tragic consequences.

Set in 1964, a camera crew follows Willie Pep, retired featherweight boxing champion. Down and out in Hartford CT, married to a woman half his age and with a drug-addled son and mounting debts, Pep decides to make a return to the ring.