Supernatural Season 11 Episode 2
Episode Name: Form and Void
Summary: Dean helps Jenna, the nurse he met after the Darkness fell, get back home safely and then sets off to help Sam deal with a town infected by a mysterious and deadly gas. However, when Jenna falls into dangerous hands, she calls Dean for help and Sam tells him to go back to her. Unfortunately for Sam, he isn't able to handle the townspeople turned monsters as easily as he thought.