Time Keepers: The Providential Cheat

Whatever had destroyed the dinosaurs was approaching Earth again. 20 extraordinary people find that they have 4 years to prevent a catastrophe, but they know that the administration will not believe them, from previous experience. When their 4-year-older timeline connects with them in a bid to prevent the annihilation of Earth in their timeline, they are elated. However, when the older timeline stops responding after a while, they assume that it has succumbed.

Their stumbling journey to prevent the catastrophe takes them to Africa and then the Pacific Islands. However, they are up against a technology that was far more advanced even 66 million years ago. In desperation, they reach out eight generations into their own past, risking their present to find a solution.

Do they succeed, or does humanity go extinct the way the dinosaurs did?