It's 1996. Josh and Emma have been neighbors their whole lives, and best friends almost as long. That is, they were best friends until last November, when Josh did something that changed everything. Things have been weird between them ever since, but when Josh gets a free AOL CD in the mail his mom makes him give it to Emma because she has a new computer. When they sign on, they're automatically logged onto their Facebook pages...thing is, Facebook hasn't been invented yet. Josh and Emma don't know how it happened, but they're looking at themselves fifteen years in the future. By refreshing their pages, they learn that making different decisions now affects the outcome of their lives later--which forces them to examine what they're doing right and wrong in the present.
I really liked the premise of this book, but I don't think it lived up to its potential. There's not a lot of characterization beyond the very basics that come into play throughout the story, so I never really felt connected with the characters. The butterfly effect element seemed way overdone and overdramatic to me--they'd change the slightest thing (like knock over a vase), refresh the page, and find out that their Facebook status was different. That said, I did enjoy following the twists and turns that Josh and Emma's lives took, and it got me thinking about my own future and whether or not I'd want to know about it now if I had the chance. Good food for thought.