Defiance

16-year-old Cassie Sullivan tries to survive in a world devastated by the waves of an alien invasion that has already decimated the population and knocked mankind back to the Stone Age.

Years into a benevolent alien occupation, mankind is still adjusting to its new overlords. Their technology initially held promise for global prosperity, but rendered most human jobs – and steady income – obsolete. When two teenagers discover the aliens are fascinated with human love and will pay for access to it, they decide to livestream their romance to make extra cash for their families.

Before they can complete renovations on their new country inn, a widowed father and his young daughter are visited by a strange group of tourists. He soon makes a chilling discovery: they are disaster junkies from the future who visit the past to witness history's greatest catastrophes—and his small town is their next stop.

Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.