“I’m just a father with a good imagination. In my imagination, I lose my children every day.”That’s the response author John Irving gave to a reader who asked how he, a father, could write The World According to Garp, a novel filled with lurid scenes of child-peril. Nearly every parent can identify with the experience of seeing the world as a giant death-trap, waiting to snatch away the children whose safety we need to ensure and whose innocence we want to prolong.A Quiet Place makes those fears explicit, following a family of four still reeling from the loss of one child while preparing for the birth of another. Also, they’re surrounded by unkillable, super-fast beasties with incredibly sensitive hearing. Any noise louder than a gasp means instant death. And kids, any parent can tell you, are sentient balls of noise.It’s to the credit of director John Krasinski, who also stars as the family patriarch, that we immediately buy into this premise and rarely question its “whys” and “hows.” Krasinski and cinematographer Charlotte Bruus Christensen confidently move the camera through spaces occupied by the family, showing not only their day to day silent lives, but their familial interactions.In fact, as impressive as the movie’s direction and world design may be, it’s really the film’s attention to family dynamics that makes it work. A Quiet Place takes time to show these characters as people trying their best to live together and support one another, lingering on kids playing games or the father teaching his son (Noah Jupe) how to fish.Krasinski’s character, haunted by the loss of his child and desperate to keep his children safe, follows the usual “stoic dad” tropes, but finds new ways of interpreting the stock figure by limiting expression to looks of concern or silent shushing. As the mother, Emily Blunt gets far more to do, nurturing her children with a silly face or a soft hand on their heads, and later trying to deliver a child without making a sound.But while Jupe’s job is mostly to react with worry to real or imagined threats, the standout here is Millicent Simmonds as the older sister. As a deaf girl living with both the guilt of her role in the younger brother’s death and a world where noise means instant death, the movie stacks a little too much drama on her character. But Simmonds manages to ground her character, making her adolescent rebellion as believable as it is ill-advised.The movie works best when its set-pieces harness our own parental fears and our concern for these characters. But it also fails when it forgets how much we’ve bought into its rules. The monster’s hearing sensitivity fluctuates in the last act, and special arrangements become fuzzy.This last part is particularly problematic, as the film too often loses track of characters while focusing on the threats facing others. Instead of fully engaging in the plight of those we see, viewers find ourselves distracted by the absence of others. Rather than build tension, this approach makes us frustrated with the characters. The most egregious example occurs when, shortly after an attack, mom and dad give one another a pep-talk about how their entire identities are built on protecting their kids. Instead of thinking, “Being a parent is tough and admirable,” we viewers find ourselves shouting (quietly, so as not to prompt an attack), “Go get your kids, morons!”Fortunately, those moments are few, and the movie finds some new way to imperil a kid, thus triggering our protective instincts and getting us drawn right back into the dangerous world of A Quiet Place.