Heartbreak is too weak a word to describe a parent’s reaction to a child’s autism. The “Independent Lens” (9 p.m., PBS, check local listings) presentation “Horse Boy” does as powerful a job as any film can showing viewers the exhausting difficulty of coping with autism’s bewildering pattern of social isolation and emotional tumult.

Temple Grandin, whose struggles with autism were the subject of a recent HBO film, is seen here discussing how she adjusted and thrived in the face of her condition.

Filmmaker Michel Orion Scott follows Rupert Isaacson and his wife, Kristin Neff, and their unusual approach to their son Rowan’s autism. By accident, Rupert discovered that Rowan was calmed by the presence of animals. And when the boy sat atop a gentle mare, his screaming jags stopped completely. After Rupert and his son took up riding, Rowan emerged from his shell, spoke readily and engaged willingly with other children.

Rupert and Kristin take this horse therapy several steps further, traveling to Mongolia, one of the world’s great horse-riding nations and the home to shamanistic centers of healing.

No one in the film suggests that a trip to Mongolia or an encounter with a shaman is a cure-all for autism. Isaacson believes that perhaps the level of personal engagement required for the adventure did wonders for his son and for the family as a whole.

• The “30 for 30” (7 p.m., ESPN) documentary “Straight Out of L.A.” looks back at the 13 seasons the Raider NFL franchise spent in Los Angeles, a time that coincided with the rise of West Coast “gangsta” rap. Seminal groups like NWA cemented their association with the team and its swagger by wearing black-and-silver Raiders gear onstage and in music videos.

Tonight’s other highlights

• The final four take the stage on “American Idol” (7 p.m., Fox).

• Rachel’s sore throat prompts major changes on “Glee” (8 p.m., Fox).

• Locke’s true motivations become clearer on “Lost” (8 p.m., ABC).

• “Frontline/World” (8 p.m., PBS, check local listings) looks at the PlayPump, a merry-go-round that uses the energy of children at play to pump clean water in remote regions.

• The competition between Cary and Alicia comes to an end on “The Good Wife” (9 p.m., CBS).

• An attack targets someone close to Anna on “V” (9 p.m., ABC).

• Julia consults an old friend on “Parenthood” (9 p.m., NBC,).

• Season two of “Ashes to Ashes” (9 p.m., BBC America) opens in 1982.

• Raylan confronts the men targeting his ex-wife on “Justified” (9 p.m., FX).

Cult choice

Teens (Robin Tunney, Fairuza Balk and Neve Campbell) dabble in the occult with grim results in the 1996 shocker “The Craft” (7 p.m., E!).