It is 1962, and Elisa Esposito-mute her whole life, orphaned as a child-is struggling with her humdrum existence as a janitor working the graveyard shift at Baltimore's Occam Aerospace Research Center. Were it not for Zelda, a protective coworker, and Giles, her loving neighbor, she doesn't know how she'd make it through the day. Then, one fateful night, she sees something she was never meant to see, the Center's most sensitive asset ever: an amphibious man, captured in the Amazon, to be studied for Cold War advancements.