It's Richard's birthday and Bailey invites him to scrub in on the case of a lifetime. Meredith hires a research assistant to help with her portal vein project. A scorned Callie gives Derek quite the shock. Meanwhile, Shane helps screen candidates for Cristina's clinical trial and meets a young expectant mother who needs his help.
Elenco: Ellen Pompeo , James Pickens Jr. , Chandra Wilson , Justin Chambers , Kevin McKidd , Jesse Williams , Patrick Dempsey , Sara Ramirez , Sandra Oh , Jessica Capshaw , Sarah Drew , Camilla Luddington , Caterina Scorsone , Giacomo Gianniotti , Kelly McCreary , Katherine Heigl , Chyler Leigh , Eric Dane , Kim Raver , T.R. Knight , Jerrika Hinton , Jason George , Isaiah Washington , Kate Walsh , Martin Henderson , Brooke Smith , Jake Borelli , Greg Germann , Chris Carmack , Tessa Ferrer , Gaius Charles , Anthony Hill , Richard Flood .