Guest Stars Marcus Giamatti as Artie Sneed Alisha Boe as Grace Clarke Nancy De Mayo as FBI Agent Lauren Stamile as Dr. Colleen Marks Jessica Tuck as Dr. Giana Luca Huntington Daly as Crash Team Nurse Colleen Foy as Paramedic Mark Atteberry as Male Doctor Andrew Lukich as Mike Mullen Craig Rhodes as Security Guard Shaan Sharma as Doctor # 2 Katie Roberts as Nurse # 2 Nathan Pelle as Thomas Knight Natisha Anderson as Nurse # 1 Lucas Kwan Peterson as Young Male Nurse