Although Nicolas Cage is becoming increasingly in danger of following John Travolta down the path of over-bloated pantomime acting, he’s certainly still watchable enough to carry a film. And it’s thanks largely to him, and to some strong support from Rose Byrne, that Knowing has some backbone to go with its (admittedly, impressive) CGI overload and apocalyptic outlook. Unfortunately, however, he’s not sturdy enough to shoulder the film’s jaw-droppingly bad ending.