 The episode opens with a flashback , which features Shane Walsh ( Jon Bernthal ) attempting to save an unconscious Rick Grimes ( Andrew Lincoln ) . Observing military personnel killing various patients , doctors , and walkers from the premises , Shane tries to carry Rick out of the hospital , to no avail . After an explosion , the hospital machines shut off , and Shane puts his ear to Rick 's chest and begins to think he has died . Distraught , Shane leaves Rick in the room and puts a hospital bed against the door to protect him from walkers . 
