"Coherence" is a micro-budget film that uses smart ideas, a great soundtrack, and the performances from its actors to sustain tension throughout, without a single physical fight until the last 10 minutes of the film. The film begins with the simple premise of a dinner party gone wrong, and uses the concept of alternate realities to expose the flaws in its characters, and that is what truly makes this film great: it has mind-bending sci-fi concepts, but these concepts are simply tools used to create more tension between the characters. Alfred Hitchcock famously described suspense as this: "A bomb is underneath the table and the public knows it, probably because they have seen the anarchist place it there. The public is aware that the bomb is going to explode at one o'clock and there is a clock in the decor. The public can see that it is quarter to one". In "Coherence", the "bomb" would be the instability of the characters and their relationships. Each one clearly has a dark side that is just beneath the surface, and the strange events that occur with the meteor make them more paranoid and less trustworthy of each other and themselves, driving them each to the brink of insanity and slowly causing their relationships with each other to crumble. The film is heavily reliant on its main actors, since it almost all takes place in one location, and there are no fancy special effects to distract you from them. There are many clever moments in which a character is acting just slightly off, and while I won't spoil why, there is a very smart explanation for this. While the very end of the film didn't quite make sense to me and felt a bit unnecessary, the rest of the film will keep you guessing about if any of the characters are truly who they say you are, and the sci-fi elements give a genuine sense of unpredictability to each moment.