TONIGHT'S MUST-SEE

"Big Brother 6," 7 p.m., CBS. This season's first live episode brings the first eviction. It also brings an explanation. Each person in the house has a past connection to another housemate. Each has been told to keep it a secret — unaware that the others also have secrets. Tonight, viewers will learn who's who.

OF NOTE

"Home Alone 2: Lost in New York" (1992), 8 p.m., ABC Family. Little Kevin (Macaulay Culkin) has been inadvertently abandoned again, this time in the city. It's a ridiculous notion but the film is still fairly fun, with lots of sight gags.

"CSI: Crime Scene Investigation," 8 p.m., CBS. A murder leads to a broader look at sports betting.

"Hooking Up" debut, 8 p.m., ABC. Over the next five weeks we'll see a year in the dating life of several New York women.

"Will & Grace," 8:30 p.m., NBC. Holidays can be tricky and funny, this show reminds us. First is an hourlong Thanksgiving episode with Will futilely trying to please Vince's mom. Meanwhile, Vince's sister (Jamie-Lynn Discala of "The Sopranos") has a secret to reveal. Then comes Christmas trouble: Karen is hosting her stepdaughter and Grace breaks a valued figurine at a party thrown by Will's mom (Blythe Danner).

"Without a Trace," 9 p.m., CBS. A juror has disappeared, and if he can't be found quickly, there will be a mistrial.