TONIGHT'S MUST-SEE

"CNN: Special Investigations Unit," 2 and 5 p.m., CNN, unless news intervenes; repeats Sunday. People keep coming up with new strategies against a seemingly invincible foe — old age. They try human growth hormones or stem-cell injections or extreme calorie restriction. Each approach is considered misguided — or even dangerous — by some experts, but there are enough positive signs to continue the search. Dr. Sanjay Gupta visits people working on all of these approaches, plus the skeptics. He draws no conclusions, but provides an interesting picture of an age-old fight.

OF LOCAL NOTE

"The 44th Annual Merrie Monarch Festival," 6 p.m., KITV. The three-day hula event concludes tonight with the hula 'auana (modern dance) followed by the festival's awards ceremony. Broadcast live from the Edith Kanaka'ole Tennis Stadium in Hilo.

—Derek Paiva

OF NOTE

"Harry Potter and the Chamber of Secrets" (2002), 7 p.m., ABC Family. The second Harry Potter film is fun enough and includes a neat turn by Kenneth Branagh as a magic professor with an inflated view of himself.

"Cold Case," 7 p.m., CBS. When fresh evidence washes up on a New Jersey shore, Lilly re-opens the 1965 case of a 4-year-old's death.

"Andy Barker, P.I.," 7 and 7:30 p.m., NBC. In a change of plans, NBC is inserting two of these comedy mini-mysteries. The first involves a doctor who may be taking advantage of his attractive patients. The second has Amy Sedaris as Lew's long-ago girlfriend, who was imprisoned for 40 years. Andy tries to prove she was framed.

"Numb3rs," 8 p.m., CBS. A painting that's worth millions is stolen from a museum just before it is scheduled to go on tour.

"Law & Order," 8 p.m., NBC. A gay actor who was killed may have been ready to out a clergyman who spoke against gays, while having gay affairs.

"Law & Order: Criminal Intent," 9 p.m., NBC. Sticky Fingaz plays a "hip hop cop" who investigates rap-world crimes.

"Ugly Betty," 9 p.m., ABC. Daniel's plans for a romance with Sofia are affected when Betty learns a secret about her.

"Saturday Night Live," 10:30 p.m., NBC. While starring in "Even Stevens," Shia LaBeouf showed signs of better things to come. He was terrific as a mentally challenged boy in "Tru Confessions"; he starred in the superb "Holes." Now he's in the movie "Disturbia" and he hosts tonight. Avril Lavigne is the musical guest.