There's a new wager between Heaven and Hell. Devil bets God that if God were to pick two young people to be the new Adam and Eve, they'd sin again. God accepts and sends a college couple to various eras, starting with the Garden of Eden.
Americans on vacation in the Caribbean take a tour of a nearby island at night and watch a local voodoo ritual. Soon after, they find themselves stranded on the island and under attack by unseen foes. One by one they meet violent ends.
A seemingly indestructible humanoid cyborg is sent from 2029 to 1984 to assassinate a waitress, whose unborn son will lead humanity in a war against the machines, while a soldier from that war is sent to protect her at all costs.