TONIGHT'S MUST-SEE

"My Name is Earl," 7 p.m., NBC. Darnell, it turns out, is in the Witness Protection Program. His wife, Joy, is underjoyed to find out. Meanwhile, Earl's next task seems easy enough — cleaning out a mailbox he used for a trash can. The problem is that it contains an old love letter from one gym worker (Will) to another (Wendy). Now Earl must get them together. Wendy is still fit; she is, after all, played by Jenny McCarthy. Will isn't. So Earl must keep an eye on her while Will gets back in shape. There could be complications.

"The O.C.," 8 p.m., Fox. Last week's so-so season-opener viewed the aftershocks of Marissa's death. Her bitter mom gave Ryan (Marissa's boyfriend) the information to find — and, perhaps, kill — Volchok, the man responsible. Seth went along, hoping to stop him. That gets resolved tonight in an adequate episode. Meanwhile, Taylor has some news about her time in Paris. And young Kaitlin is quickly getting in trouble.

OF NOTE

"Ugly Betty," 7 p.m., ABC. Salma Hayek, who also is one of the show's producers, returns as the demanding Sofia, causing trouble. Meanwhile, Betty gets to write a review of an upscale hotel.

" 'Til Death," 7 p.m., Fox. Eddie (Brad Garrett) manages to create a potential feud between his pleasant neighbor and her mother-in-law.

"Happy Hour," 7:30 p.m., Fox. Ignoring Larry's solid advice, Henry dates a woman (Rachel Boston of "American Dreams") who is both beautiful and dangerous. Meanwhile, Amanda meets an old college friend who has now become judgmental.

"The Office," 7:30 p.m., NBC. With word arriving that the office will be closed, people drift into fantasies about what else they would do with their lives.

"Grey's Anatomy," 8 p.m., ABC. The guys on this show have never been the bonding type, but tonight they go on a camping trip together. Meanwhile, one case has Addison and Callie working together, another has Meredith and Mark Sloan. Also, Bailey confronts Cristina about her behavior.

"CSI: Crime Scene Investigation," 8 p.m., CBS. A killer helpfully leaves miniature replicas of the crime scenes.

"Shark," 9 p.m., CBS. An 8-year-old girl has been kidnapped and killed. Now Sebastian worries that this is related to a 1992 case in which he was the defense attorney.

"ER," 9 p.m., NBC. A patient arrives with what seems to be a simple flu; soon, however, the situation accelerates. Meanwhile, Abby and Kovac try to hire a nanny. And Gates and Neela argue with each other at a hospital board meeting.