After decades of planning, the contagion was unleashed, and overnight hundreds of millions died and came back as rampaging, undead monsters. The living that had been lucky enough to survive the first day of carnage, lucky enough to be in the right place, and lucky enough that some of them had the skills to survive soon found out there was much more to worry about than just zombies.

Isolated and left on their own at a wild animal safari park at the beginning of a zombie uprising, the boys and girls from the school field trip must learn how to survive on their own. They are safe behind the tall fences and strong walls, but what about all the wild animals inside the gates with them?

It all starts with a single dead person coming back to life. Within three days, the undead have taken over most of town. Despite heroic efforts and swift initiatives from the government, disaster keeps spiraling. Soon, the infection reaches the nation's borders, threatening to become a worldwide pandemic.

Jack Walker and Michael Talbot come from two worlds; the same, yet different. They both find themselves transported into an alien one, where things aren’t as they seem. While it appears similar to the ones they come from, there are some terrifying differences. Is it a dream? Or has reality been somehow warped? Jack comes from a world filled with nocturnal creatures that were once human, but now seek to destroy the last vestiges of humanity.

More than two centuries after World War III poisoned the planet, the final bastion of humanity lives on massive airships circling the globe in search of a habitable area to call home. Aging and outdated, most of the ships plummeted back to Earth long ago. The only thing keeping the two surviving lifeboats in the sky are Hell Divers - men and women who risk their lives by skydiving to the surface to scavenge for parts the ships desperately need.