Apocalypse started because of man's god-playing and madness. An airborne virus was shot up to the sky that was supposed to cause immortality, only it gave more life for those who are already dead.
Job thought that they are saved from Doctor Galleon's work, only the true horror begins when the secret of their rescuers sparked his and Rachel's curiosity.
A man is still not done playing god. They are not saved yet. None of them are when they are in the deep territory of a living Grim Reaper.