This is part 33 of my 100% collectible and challenge walkthrough of Zombie Army 4: Dead War. In this part I go through the "Ground Zero" which is chapter 1 of the DLC Terror Lab mission. I'll show you how to find all collectibles as well has how to complete the chapter's challenge. TIMESTAMPS: Document 1/1: Zombie Hand 1/1: Comic 1/1: Challenge - get 50 headshots.