TONIGHT'S MUST-SEE

"Lost," 8 p.m., ABC; also, "Lost: Revelation," 7 p.m. Whenever this terrific show takes a break, there are understandable groans. Now it's back and new. First is a recap that traces what has happened so far to both groups — the original people we met last season and the separate, tail-section survivors. Then comes a new episode. Claire is losing confidence in Charlie, who has been protective of her and her baby. Jack frets about Kate's attraction to Sawyer.

"South Beach," 4 p.m., UPN (KIKU). Two beefy Brooklyn guys hop in a car and go to Miami in search of new lives. This being television, they find them within hours. One guy has a pool job spraying water on bikini beauties. He also overhears plans for a $4 million robbery. Another rescues someone who turns out to be a club owner and gives him a job. You'll believe this if you believe that his ex-girlfriend, a struggling model, has worked a few months and has her face on giant billboards. Vanessa L. Williams, who should have better things to do, stars with newcomers.

OF NOTE

"E-Ring," 7 p.m., NBC. An Amsterdam lab has been discovered preparing a plague virus.

"Walking the Bible," 8 p.m., PBS. This hour visits Egypt and looks at the possible sites of several biblical stories.

"The Biggest Loser: Special Edition," 8 p.m., NBC. Here's a one-shot special, with two engaged couples trying to see which one can lose the most weight. Naturally, cruel temptations are included. There's also a $50,000 prize at stake.

"Country Boys" conclusion, 9 p.m., PBS. This slow-but-eloquent documentary has traced three years in the lives of two Appalachian teens. Now they begin their senior year, trying to survive family tragedies. Cody Perkins — who was 12 when his dad killed his seventh wife and himself — has a girlfriend, a good school attendance record and an interest in music and religion. Chris Johnson is trying desperately to catch up in school after working almost full-time. Now both face triumphs and crises.

"Law & Order," 9 p.m., NBC. When a mob accountant is slain, a corrupt cop becomes involved. The result could spiral into the police hierarchy.

"CSI: NY," 9 p.m., CBS. A tram operator dies just days before his retirement. Usually, that fate is reserved for TV cops.

"Invasion," 9 p.m., ABC. After a long rest, this well-made show reclaims its time slot. ("Alias" is expected to return in March to start its final episodes.) Tonight, Russell (Eddie Cibrian) finally confronts his ex-wife (Kari Matchett) about her weird behavior since she was found in the Everglades. Meanwhile, their son (Evan Peters) meets a girl who's lovely but odd.