A seemingly perfect couple's new lodger begins to blur the lines of their lives, escalating from an overly familiar presence to a dangerous obsession. Marisa and Jake, a couple struggling with fertility, welcome Kate as a roommate, hoping her rent will ease their financial strain as they try for a baby. However, Kate's increasing disregard for personal boundaries and her unsettling familiarity with Jake begin to erode Marisa's sense of security. As Marisa's attempts to conceive become more fraught, Kate's obsession with the couple and their future child intensifies, leading Marisa to question Kate's true identity and motives, risking her own carefully constructed life in the process.

The premise of Magpie sets up a tense psychological thriller that delves into themes of envy, possession, and the dark side of desire. The narrative appears designed to keep readers guessing, with a focus on the unraveling of a seemingly perfect life under the influence of an obsessive outsider. The story's exploration of domestic relationships and the pressures of starting a family suggests a compelling, character-driven plot. The description indicates a novel that thrives on suspense and unexpected twists, aiming to deliver a disquieting reading experience.