Becky Green is obsessed with stalking her childhood friend Chloe Fairbourne's curated social media presence. Chloe lives a charmed life with an adoring husband and a circle of high-achieving friends, and Becky can't help but take interest in a world that contrasts so starkly with her own.

When Chloe suddenly dies, Becky assumes a new identity and infiltrates the lives of Chloe's closest friends to find out what happened to her. Through her alter-ego Sasha, Becky becomes a powerful, popular, well-connected somebody.

However, the pretense soon obscures and conflates reality, and she learns that Chloe's real life had not been nearly as perfect as it was portrayed to be online. As Becky gets deeper into her con and Chloe's inner circle, she risks losing herself completely.