Chris has been expecting his return to home from summer break, but he never imagined it would be the most thrilling moment of his life.
The entire city is enveloped by an enigmatic force overnight, transforming it into a post-apocalyptic world filled with zombies. Chris, his sister Emma, and their dog Beethoven boldly jump from the skies together, but they quickly find themselves in an unending state of danger.
During the lengthy and thrilling escape, they break into an abandoned base that is full of unknown threats and opportunities, and it was previously the covert stronghold of a mystery organization. In order to figure out the secret of the base and find a way out to survive, Chris and his companions must navigate through a variety of challenges.