While investigating the disappearance of a missing man, Sam and Dean have to break in to the place where he disappeared, but they get caught, and Dean is shot and killed by the owner. When Sam wakes up the next morning he is shocked, Dean is alive, but as the day continues Sam realizes that they are re-living the previous day so he tries to stop Dean from getting shot, but he fails and Dean dies again... and again... and again, so Sam has to learn how to continue on without his brother.