We're going to rewind the clock. And we're going to go back to the time when the concept of ''Christmas'' didn't exist. And we're going to step into the shoes of three people who were hearing the news of Christ's birth for the first time. No traditions attached to it; no expectations; no familiar songs to give it meaning. Just this shocking news of something that had happened-or was about to happen. And we're going to look at how they responded and how it changed them.