The best documentaries take us to places we would never go, and show us things we might not want to see. “Love & Diane” (8 p.m., PBS, check local listings) is that kind of film. A presentation of “P.O.V.,” the documentary follows a mother and daughter from a troubled urban family as they try to escape the demons that consumed their relatives. The mother of six children, Diane spent much of the 1980s in search of her next hit of crack cocaine. Her children were scattered throughout the foster-care system or housed in group homes. Once clean and sober she reassembled her family, including her daughter Love, who suffers from depression and HIV and who just gave birth to a baby boy.

Shot in cinema verite style, without narration or expert commentary, “Love” allows its subjects to describe their hopes for the future as well as their harrowing past, including several generations of depression, rampant alcoholism and the near certainty of early death. Offering more than mere voyeurism, “Love” shatters common assumptions and asks us to ponder phrases like “the cycle of poverty” or “one day at a time.”

Tonight’s other highlights

• Singer and actress Reba McEntire will receive the Johnny Cash Visionary Award at the 2004 Flame Worthy Video Music Awards (7 p.m., CMT).
• Votes are tallied on “American Idol” (7:30 p.m., Fox).
• Julie’s wedding shower on “The O.C.” (8 p.m., Fox).
• Scheduled on “48 Hours Investigates” (9 p.m., CBS): new evidence emerges about Princess Diana’s death.