Meet Savi, a successful career woman working toward the next phase in her life—both professional and personal—simultaneously bucking for partner at her law firm while she and her husband, Harry, try to start a family of their own. Savi's free-spirited and capricious baby sister, Josselyn, couldn't be more different—living single, serial dating and partying, and regularly leaning on her big sister along the way. Their common best friend, April, a recent widow and mother of two, is rebuilding her life after tragedy and learning to move forward, with the support and guidance of her closest girlfriends. And friend Karen, a successful therapist with her own practice, reconnects with the girls after her involvement in a complicated relationship with a patient goes far too deep.

When the entire world blacks out for two minutes and seventeen seconds, everyone sees a flash of their own future 6 months from the present. For some, the future is hopeful, while for others, it is unexpected. For a few, it doesn't seem to exist. Knowing their fate will alter each person's life, destinies will be changed.

In the year 2149, the world is dying. The planet is overdeveloped and overcrowded, with the majority of plant and animal life extinct. The future of mankind is in jeopardy, and its only hope for survival is in the distant past. An ordinary family goes on an extraordinary journey back in time to prehistoric Earth as a part of a massive expedition to save the human race.