These days, The Walking Dead is one of the biggest shows on TV, with a massively successful series for AMC, a video game series from Telltale Games and a prose series from Macmillan all having been spun out of Robert Kirkman's original comic book. But it nearly didn't happen.

In this exclusive clip from Comics in Focus: The Image Revolution, Kirkman and Image Comics publisher Eric Stephenson tell the story of what Kirkman had to do in order to convince Image to publish the series in the first place -- including the unexpected revelation of just what the writer told Image was behind the zombie apocalypse.

STORY: Image Comics Announces Third Expo for Jan. 2014

The feature-length Comics in Focus: The Image Revolution, directed by Patrick Meaney and produced by Sequart Research & Literacy Organization in conjunction with Respect Films, is currently available for pre-order, with a DVD and digital release scheduled for January 2014.