Stephen King adaptations don’t always work out, and this is another instance of that. There’s a strange, unseen force—like a malevolent presence—that invades people's minds and dreams, causing them to become violent and destructive after receiving an odd transmission through their cell phones. It’s about the threat to humankind as these individuals are transformed into killers. A man portrayed by Cusack is looking for his son, and believes he can rescue everyone! The plot feels disjointed, and frankly, the final scene ranks among the most disappointing I've encountered.

Source on TMDB