As outlined by the "Book of Revelations", it appears that a mysterious nomad has started the apocalpse as the signs outlined in the famous writings seem to be coming to pass.
A woman who has started to recognise these events herself is the pregnant Abby Quinn (Demi Moore). Also on the case is Father Lucci who has been assigned to this case by the Vatican itself to determine whether the Apocalypse is in fact on the doorstep preparing to ring the door bell.
Yet he dismisses the occurences as being natural phenomenon coinciding with each other purely by chance.
However Abby has reason to beleive that the fear is real and that the unfolding events that are destined to happen will affect the future of her unborn baby.
She now sets out alone to avert the disaster that will, for certain, be the end of the world.