The Walking Dead Season One will rise from the grave with 400 Days, a single-episode side story coming this summer. The DLC episode was revealed at Sony's press conference last night, and Telltale Games released a trailer and more details today.
Taking place over the first 400 days of the undead epidemic, 400 Days' five mini-episodes each cross paths with a rural truck stop. You can play them in any order, and will find decisions from Season One influence 400 Days, and choices in 400 Days will influence Season Two when it arrives this fall.
400 Days will cost $5 and will require the first episode of Season One to play. Telltale recommends you play through the first season beforehand, but it's a free country--especially with everybody turned into zombies.