Guest Stars Jesse Williams as Dr. Jackson Avery Sarah Drew as Dr. April Kepner Jason George as Dr. Ben Warren Nora Zehetner as Dr. Reed Adamson Alan Mandell as Henry Stamm Amy Farrington as Mary May Austin Highsmith Garces as Amber Courier Demi Lovato as Hayley May Emily Bergl as Trisha Jonathan Goldstein as Ken May Marion Ross as Betty Donahue Co Starring Mark Saul as Dr. Steve Mostow Gloria Garayua as Dr. Graciella Guzman Denice J. Sealy as Nurse Regi Davis as Dr. Kevin Fisher