Doomsday starts in the aftermath of 9/11, when the U.S. government institutes a secret think tank featuring the most creative minds in science and entertainment that is tasked with dreaming up man-made disaster scenarios and their possible solutions. Because the hypothetical ideas are deemed extremely dangerous, the list is sealed and the program shut down. But when a catastrophe occurs that's ripped from the pages of the missing doomsday book, the team is brought back years later to prevent the disasters of their own making.