It's the present or the very new future and people from the hundreds of years in the future are traveling back in time and inhabiting the bodies of people who die. They know about their deaths from future records. The first episode establishes the characters. Among them are an FBI Agent (Eric McCormack), a doctor named Marcy (who mistakingly inhabits the body of a mentally retarded girl and has some problems because of it), Trevor (a hundred year old man in the body of a teenager), Philip (computer wiz in the body of a heroin addict), and Carly (a single African American woman with a new baby). The second episode has them on a mission to stop an anti-matter device from detonating and killing 11,000 people. They believe if they do this they'll prevent a war that happens over fusion energy. By mid-way through the season we find out that their main mission was to deflect a comet that would have hit earth and killed 90 million people and started a fusion arms war which nearly causes their extinction. But their everyday lives begin to interfere and a threat pops up from the future-a rebel group that wants to stop them. The last episode has the revelation that they've indeed changed the future but not for the better...
This is a very cool, intriguing time-travel series along the lines of THE 4400. Recommended. Looking forward to the next season.