The film loosely follows an English couple that travels to Cave-In-Rock, Illinois, United States to attend the ninth annual Gathering of the Juggalos.
Interviews about the fan base are conducted with artists Anybody Killa, Ice-T, Afroman, Boondox, Blaze Ya Dead Homie, Three 6 Mafia, Twiztid, and Insane Clown Posse.
Concert footage of the interviewed artists as well as the supergroups Psychopathic Rydas and Dark Lotus is included.
[1] The focus of A Family Underground is directed toward "the true story of ICP", their Juggalo fan base.
[3][4][5] In 2010, the documentary was reissued as part of the "Nuclear Edition" of Insane Clown Posse's album Bang!