The whole idea of the show is this.
It started off as a normal day, then all at once every one (world-wide) blacked out for 2.17 minutes. While they are blacked out they had a "dream" of what they will be doing exactly 6 months from now, April 29, 2010.
Mark Benford is an FBI agent that is investigating what caused this even. Meanwhile there is a lot of other people's who's lives have been changed because of they just had a glimpse of the no so distant future.
It looks like it going to be an interesting show. Hopefully it does not get dragged out with too much drama like Jericho or Heroes.