Julie

Julie is a teenage babysitter who moves through the Tench household with the easy, unremarkable confidence of a normal kid doing an ordinary job. She keeps an eye on young Brian, chats amiably, and seems entirely untouched by the strange quiet that surrounds the boy — a picture of ordinary adolescence set against a family quietly unraveling.

Jordyn DiNatale plays Julie with a breezy naturalism that becomes unsettling by contrast: everyone around her senses something wrong, and she alone doesn't. Mindhunter uses that gap between her cheerful obliviousness and the audience's dread to build tension without a single raised voice, letting ordinariness itself feel unnerving.