Grey's Anatomy Season 8 Episode 12

Richard performs his 10,000th surgery -- a liver transplant involving bickering sisters (Peri Gilpin and Nia Vardalos). Meanwhile, Adele Webber is found aimlessly wandering the streets; Derek and Lexie take on a supposedly inoperable neuroblastoma case; Teddy and Cristina try to steal a case from Alex and Dr. McQueen, countermanding Owen's orders; and Meredith searches for a specialty -- with Ellis Grey's ghost.