From NBC's official press release:

Neela has a crazy recurring dream about the day she was trying to save a girl with sickle cell anemia.  Meanwhile, she goes to an attending interview and sees an old colleague.  Gates tries to save a patient who jumped out of a window during his sleep.

ER stars Parminder Nagra as Dr. Neela Rasgotra, Linda Cardellini as Nurse Samantha Taggart, Scott Grimes as Dr. Archie Morris, John Stamos as Dr. Tony Gates, David Lyons as Dr. Simon Brenner, Angela Bassett as Dr. Catherine Banfield.

Source: NBC
(Image Courtesy of NBC)