When it is reported by Ruth Walker (Guest Star Gail O'’Grady) that her two year-old granddaughter, Sierra Walker, is missing Detectives Olivia Benson (Mariska Hargitay) and Elliot Stabler (Christopher Meloni) investigate. After rounds of interrogation and a failed Amber Alert, Benson and Stabler believe that the prime suspect is none other than Sierra’s young and irresponsible mother, Ashlee Walker (Guest Star Hilary Duff). Also starring: Richard Belzer (Detective John Munch), Dann Florek (Captain Donald Cragen), Ice-T (Detective Odafin Tutuola), Michaela McManus (A.D.A Kim Greylek), Stephanie March (ADA Alexandra Cabot), Tamara Tunie (Dr. Melinda Warner), and B.D. Wong (Dr. George Huang).