The Vast of Night is a mystery that can't sustain itself. It's fine to try and build up to a big reveal, but along the way we need to be invested in more than just "the answer." Unfortunately, the script for The Vast of Night is wholly invested in two teenagers chasing down a mysterious signal, but fails to show interest in their interior lives, their wants, desires, or really any kind of conflict beyond, "Let's find out what this signal means." The film's saving grace is director Andrew Patterson, who gives his low-budget feature …