TONIGHT'S MUST-SEE

"Shaq's Big Challenge" debut, 8 p.m., ABC. When Shaquille O'Neal talks, people tend to pay attention. Now he helps six kids fight obesity, against immense odds. One boy puts french fries under the bun of his hamburger; another averages five hours a day of video games. A girl has 50 percent body fat. Several kids can't do one push-up. This is an earnest reality show, but a tough one to watch. Some of the kids face major medical risks.

OF NOTE

"Critical Situation" debut, 6 p.m., National Geographic. The opener looks at one of the most famous of critical situations, when technical troubles stranded astronauts in Apollo 13, seemingly unable to get back to Earth.

"America's Got Talent," 7 p.m., NBC. Here are the New York auditions.

"House," 8 p.m., Fox. The relentless Detective Tritter is closing in on Dr. House, in this rerun. Tonight, he interrogates staffers about House's drug use. Also, the doc is getting less Vicodin and his performance is wobbling.

"Nova: The Great Inca Rebellion," 8 p.m., PBS. In the history told by the Spanish, a handful of conquistadors easily conquered the massive Inca armies in 1532. Now we watch archaeologists find clues to the truth. It's a complex story of political deals and deal-breaking, told in beautiful South American settings.

"Law & Order: Special Victims Unit," 9 p.m., NBC. A lawyer for the mob and his family are killed, in this rerun. A son survived, but was traumatized; a daughter wants to cover up her night of drugs and alcohol.

"P.O.V.: Sierra Leone's Refugee All Stars," 10 p.m., PBS. The horrors of Sierra Leone's civil war left deep scars. Some men were killed, others had a hand chopped off. Many retreated to a refugee camp in Guinea. In that bleak setting, something impressive emerged. We meet the six members of a reggae-flavored all-star band. We also see them return, hesitantly, to their home village.