8 pm/ET CW
An unexpected trip to the Phantom Zone with Clark turns Lois into a murderous villain bent on terrorizing Metropolis. While Lois can't quite say the Devil made her do it, she can place the blame on Zod's wife, Faora, who has taken over her body. Once again, it's up to Clark to save the day and send Faora back where she belongs. - Rhoda Charles
For full episodes of Smallville, visit ourOnline Video Guide.
9:31 pm/ET NBC
The Emmy darling (it took home seven 2008 statuettes, including Outstanding Comedy Series) continues to rock on with yet another fabulous guest star. Oprah Winfrey, appearing as herself, is assigned a seat right next to Liz on an airplane. It likely won't be a top-flight experience for Oprah, as a medicated and sky-high Liz hounds the sage talk-show host for personal advice. Back at 30 Rock, Tracy and Jenna, feuding as always, switch roles to determine whose life is harder. Then there's Jack, whose value system is tested by Kenneth and an Olympics debacle. - Dean Maurer
For full episodes of 30 Rock, visit ourOnline Video Guide.
CSI: Crime Scene Investigation
9 pm/ET CBS
Everyone's favorite dominatrix, Lady Heather (the tantalizing Melinda Clarke), returns in an emotionally charged episode in which Grissom seeks her help to solve a murder that involves S&M. In addition, the episode is named for Linkin Park's single "Leave Out All the Rest," which is used prominently throughout the hour to underscore the unresolved feelings Grissom has for Sara. - Tim Holland
For clips of CSI, visit our Online Video Guide.
10 pm/ET NBC
Morris has gone from comic relief to respected doctor and good friend. Tonight he takes another step in moving away from his goofy roots when he accepts a role recently vacated as a result of Pratt's death: big brother and mentor to Chaz. The transition doesn't exactly go smoothly when Banfield, who has already gone a few rounds with Morris, takes issue with his methods. But Morris appears ready to defend himself, even with the arrival of Banfield's husband (played by Courtney B. Vance, Angela Bassett's real-life spouse) at County. - Rhoda Charles
For clips of ER, visit ourOnline Video Guide.
Life on Mars
10:01 pm/ET ABC
Whoopi Goldberg takes a trip back to the '70s when she guest stars tonight as a DJ who goes by the handle Brother Lovebutter. In the episode, racial tensions erupt between the black and Puerto Rican communities when a black girl is found thrown from a rooftop, and the racial attitudes of some squad members don't help. Sam works the case with officer Fletcher Bellow, a mentor to Sam in 2008 who doesn't recognize him in 1973. - Fred Mitchell
For clips of Life on Mars, visit our Online Video Guide.