How It Ends is one of those post apocalyptic movies that test one’s patience for the unanswerable.
A father (Forest Whitaker) and future son-in-law (Theo James) hit the road to save their daughter/future wife (Kat James) from a seismic event that has knocked out all power and common sense. In between car chases and brazen yahoo citizenry typical to end of world scenarios like this the two try to understand each other and what is going on in the world. A teen spirit of Native American persuasion (Grace Dove) tags along, functioning as auto mechanic and quasi daughter substitute.
How It Ends explores the possibility of family for these three but never really gets around to establishing it or defining it. Uncomfortable accommodations are made, some understanding and empathy is achieved before it all falls apart. The only options are to leave or die before the deadly storm rolls in.
That is the metaphor. Humanity is incapable of knowing itself beyond its own limited vision. That is life and that is How It Ends