The screenplay was penned by , who would go on to become the architect of the entire Conjuring universe. Dauberman wrote Annabelle: Creation (2017), The Nun (2018), and Annabelle Comes Home (2019), as well as the two It films. For this first outing, Dauberman crafted a 1970s-set retro horror film heavily inspired by Rosemary’s Baby and The Exorcist , focusing on the dread of pregnancy and the invasion of the home.