* Dancing with the Stars (9 pm/ET ABC)
The first results show of Season 8 features a new element for the series: a dance-off between the bottom two couples facing elimination. But before someone makes the season's inaugural exit, there will be songs from injured contestant Jewel ("Somewhere over the Rainbow") and swing band Big Bad Voodoo Daddy ("Calloway Boogie"). Also: Choreographer Michel Rooney takes on the season's first "Stars of Dance" performance with a Busby Berkeley-inspired number.
* The Mentalist (9 pm/ET CBS)
The fascination in this crime drama is in watching Patrick Jane watch people, and seeing how he sees what most people miss. What happens when you take away his powers of observation? That's the challenge tonight when Jane loses his sight as a result of an explosion and has to rely on his other senses during the murder investigation of a financial adviser.
* Law & Order: Special Victims Unit (10 pm/ET NBC)
Comedian Carol Burnett does a dramatic turn when she guest stars tonight as Birdie Sulloway, a former dancer. Benson and Stabler arrive at Birdie's penthouse to question her because she owns a strip club where a murdered woman worked. Both Birdie and her doting nephew, Chet (Matthew Lillard), assist the detectives, but the focus of the investigation shifts when the prime suspect dies and the emergence of a vigilante comes to light.
It's good to be the countess. Yes, Countess LuAnn de Lesseps has had an eventful summer in the Hamptons, swirling in the social scene and penning a book on manners and etiquette. (Although Bethenny questions whether LuAnn knows about such things.) As the summer winds down, we can count on the countess to prepare daughter Victoria for boarding school. LuAnn is also the hot topic of Ramona and Bethenny's dirt-flying dish-a-thon. Later, Bethenny reaches out to the countess during a meal - but the results may be hard to swallow.
* Without a Trace (10:01 pm/ET CBS)
Vanessa Marcil appears tonight in the first of a multiple-story arc. Marcil plays a New York social worker and a potential love interest for Eric Close's Martin Fitzgerald. Tonight, the agents try to find a trial consultant who vanishes while working on a high-profile civil case. Also: Jack and Sam deal with the presence of Brian, who spends more time with Finn.