Desperate to reignite the spark in their crumbling relationship, Bryan (Aaron Paul) and Cassie (Emily Ratajkowski) rent a beautiful, romantic villa in the Italian countryside using a home-sharing website called "Welcome Home." Soon after settling in, Cassie befriends Federico (Riccardo Scamarcio), the kind, handsome stranger who lives just down the road. Bryan is instantly threatened by Federico's good looks and charm, and Cassie becomes upset by Bryan's jealousy. Federico uses this jealousy to manipulate the couple into turning against each other. Bryan and Cassie find themselves caught in a sexy, voyeuristic, and increasingly dangerous game of cat and mouse where they discover the person you love the most may be the person you can trust the least.