This movie, made in twenty-oh-seven, is an intuitionbased study of some kind of flaw in spacetime, or in mind, or both. Its rather confusing theme is far from clear, and it bounces between realities in a somewhat baffling way.
In it, the character Jim Hanson apparently dies, and the effect on his wife Linda of the traumatic death-experience is the nucleus of the rest of the movie. For, each time that she sleeps, Linda seems to "shift" universes, perhaps entering a parallel universe in which Jim has not died. Or, it is also possible that she remains in this universe, but time-travels back to the time before his death.
A psychiatrist cannot explain what is happening, nor can a religious leader; it is quite beyond their comprehension.
Linda finally sees this as an opportunity to prevent the death of Jim. So, she goes back to the place and time of the accident, connects with Jim over cellphone, tells him to turn around, and ends up actually causing the accident that killed him.
This is a story about the Power of Love. But it also teaches that you cannot avoid your destiny: At least, there do exist events in the "future" that you cannot change. A subplot is that Jim is planning to have an affair with a lady at work, which would have blasted the marriage between him and Linda into nonexistence. But, at the last minute, he changes his mind, and wants sincerely to repair his marriage with Linda.
The ending might not be "happily ever after," but so few are, in real life.