Seventy thousand years ago, the human race almost went extinct. We survived, but no one knows how.

Until now. The countdown to the next stage of human evolution is about to begin, and humanity might not survive this time. The Immari are good at keeping secrets. For 2,000 years, they've hidden the truth about human evolution. They've also searched for an ancient enemy - a threat that could wipe out the human race. Now the search is over.

At the end of the world, a groundbreaking scientific experiment will change everything. Dr. Laura Reynolds had it all. A job she loved. The respect of her peers. Student debt she was slowly chipping away at. And one day, it all went away. She saw the wrong thing—a colleague's mistake. And to escape, he framed her. Laura's only option is to join a secretive research project in Antarctica, where she hopes to keep practicing medicine and one day get her life back. But soon after arriving, she realizes that things aren't what they seem in this advanced facility.

The ice is coming. It was the last thing we expected, but the world is freezing. A new ice age has dawned. Billions have fled the glaciers. A cataclysmic war is coming. In orbit, a group of scientists are running the Winter Experiments, a last-ditch attempt to understand why the planet is cooling. None of the climate models they build make sense. But then they discover an anomaly, an unexplained variation in solar radiation...and something else. Close to the burning edge of the sun, they catch a fleeting glimpse of something that shouldn’t be there....

Dr. Sam Anderson is one of the most celebrated scientists in history. Ten years ago, he invented a device that changed the world forever. Now his life is about to be ripped apart—and his own creation may be to blame. One fateful morning, Sam discovers that his girlfriend has been murdered and that his daughter is accused of the crime. Sam believes she's innocent, but he can't prove it. There's only one thing he can do to save his daughter: confess to the crime. And so he does. But in the future, murderers aren't sent to prison. They're sent to the past.

In Atlanta, Dr. Peyton Shaw is awakened by the phone call she has dreaded for years. As the CDC's leading epidemiologist, she's among the first responders to outbreaks around the world. It's a lonely and dangerous job, but it's her life - and she's good at it. This time she may have met her match. In Kenya, an Ebola-like pathogen has infected two Americans. One lies at death's door. With the clock ticking, Peyton assembles her team and joins personnel from the Kenyan Ministry of Health and the WHO.