Of the 24 semifinalists chosen last week, the Top 12 girls will perform for America for the first time. Then its up to the viewers to vote for their favorites. Who will survive and who will go home?
Performing tonight are

Ayla Brown,

Becky O'Donohue,

Brenna Gethers,

Heather Cox,

Katharine McPhee,

Kellie Pickler,

Kinnik Sky,

Lisa Tucker,

Mandisa,

Melissa McGhee,

Paris Bennett,

Stevie Scott

Cheryl believes she's attending a tasteful lingerie party, but is shocked to learn the hostess is selling sex toys and Cheryl buys one, but won't tell Jim.

Scientists' efforts to identify and understand neutrinos, unseen building blocks of the universe, are chronicled, beginning in 1930 with Austrian physicist Wolfgang Pauli's observations about a decaying radioactive atomic nucleus. Included are comments from astrophysicist John Bahcall, who calculated the sun's theoretical neutrino output during the 1960s; and Nobel Prize winner Raymond Davis Jr., who built a neutrino trap in a South Dakota gold mine.

Alan and Denny defend a man charged with murder after he euthanized his wife with Alzheimers.



Meanwhile, long-lost family members return when Shirley's ex-husband asks her to be "best man" at his wedding and Paul tracks down his estranged daughter.

Claudette further aggravates her illness as she continues to aggressively interrogate Kleavon Gardner. The Strike Team works with the Chief of a citywide task force to investigate the murder of a drug dealer's girlfriend and her daughter. Meanwhile, Kavanaugh attempts to discover how Vic acquired the $65,000 that was given to Corrine, and Ronnie is up next for questioning in the IAD investigation.

TONIGHT: Author of Assassination Vacation, Sarah Vowell! Also, Nate and Rob Corddry with "Brother vs. Brother."

TONIGHT: Stephen Colbert welcomes the author of Natural Radiance: Awakening to Your Great Perfection, Lama Surya Das!

The contestants' first challenge involves selling fruit and vegetables on the streets of Hackney in London's East End. Their aim is to make the most profit and avoid being fired at the end of the day.