Pictured: LL COOL J (Special Agent Sam Hanna), Michelle Trachtenberg (Lily Lockhart), and Chris O'Donnell (Special Agent G. Callen). The NCIS: Los Angeles team searches for a motive when a Senator’s daughter is attacked. Meanwhile, Deeks and Nell partner up to help Sam and Callen bring the daughter to safety and Kensi receives the perfect holiday gift from one of her co-workers, on NCIS: LOS ANGELES, Tuesday, Dec. 17 (9:00-10:01 PM, ET/PT) on the CBS Television Network. Michelle Trachtenberg Guest Stars as Lily Lockhart, the Senator’s Daughter. Photo: Richard Foreman/CBS ©2013 CBS Broadcasting, Inc. All Rights Reserved.