A gas tanker explodes on a Seattle highway, causing multiple injuries, including paramedic Matthew. Meredith and Jo help a frantic mother whose child is suffering from a mysterious illness. Owen bonds with a young boy whose parents are in critical condition. Meanwhile true colors are revealed when Alex is forced to work with Jo's boyfriend on an ailing patient.
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 .