AMC teased a snippet from the upcoming fourth season of "The Walking Dead" last night, as much an attempt to draw audiences into its struggling Detroit drama "Low Winter Sun" as to promote the returning horror series. You'll have to wait until October 13 for the return of the highly rated zombie show, but you can glimpse Michonne (Danai Gurira) grappling with some particularly persistent members of the undead after going out for a ride below.