 After entering the headquarters of the Centers for Disease Control and Prevention , the survivors are confronted by Dr. Edwin Jenner ( Noah Emmerich ) , who is armed with an automatic carbine . Jenner allows the group to stay on the condition that they all must undertake a blood test , to which Rick agrees . As the group indulge in various luxuries such as showers and wine , many of them are perplexed with the situation . Jenner reveals that he is the only medical personnel dedicated to eradicating the walker illness ; many of the medical staff have returned to their families or have committed suicide . Meanwhile , a drunk Shane confronts Lori Grimes ( Sarah Wayne Callies ) about her callous attitude towards him . As the argument begins to peak , Shane attempts to rape Lori , but backs off when she scratches him on the neck . 
