TONIGHT'S MUST-SEE

"I Walk the Line: A Night for Johnny Cash," 7 p.m., CBS. Last year, CBS had a Ray Charles tribute (leading into the "Ray" movie) that was sometimes wonderful. Now it does that for Cash. Joaquin Phoenix and Reese Witherspoon, stars of the "I Walk the Line" movie, will be there. So will Jerry Lee Lewis (Cash's contemporary) and Kris Kristofferson (his colleague in "The Highwaymen"). Lots of country people will perform, including Martina McBride, Brad Paisley, Alison Krauss, Dwight Yoakam and Montgomery Gentry. There will also be performers from pop and rock. They include Sheryl Crow, Norah Jones, U2, Kid Rock and the Foo Fighters.

"Lost," 8 p.m. to 9:05, ABC. This season, viewers have been intrigued and puzzled by the show's new characters. All or most were from the tail-section of the plane. They washed up on a different part of the island than the main characters. But what happened next? Tonight's 65-minute episode flashes back to their view of the crash and the 48 days that followed. It's like getting "Lost" all over again.

OF NOTE

"E-Ring," 7 p.m., NBC. In a reverse of the usual process, an armed Christian group has taken over a mosque in the Detroit area. J.T. and his old comrades want to intervene but the law says it's up to the FBI, not the Pentagon.

"That '70s Show," 7 p.m., Fox. Hyde had intended to propose to Jackie but didn't. In the aftermath he somehow managed to marry a stranger. Now it's Kelso's turn to propose to Jackie.

"Stacked," 7:30 p.m., Fox. Skyler's former plain-Jane friend visits. Now she's beautiful (played by Jenny McCarthy) and engaged. The result is so-so.

"Invasion," 9:05 p.m., ABC. Just how much have people been altered since the storm? Mariel begins to question why she's become distant from her kids. She also makes a shocking discovery. Meanwhile, Dave learns who owns the wedding band. And when a baby is found at the ranger station, a woman — suspected of being the mom — says she knows nothing about it.

"Law & Order," 9 p.m., NBC. A murder might be linked to a citizens' group fighting illegal immigration.

"CSI: NY," 9 p.m., CBS. Shades of the old West: Someone is shot after arguments over a poker game.