Tracy Sierra is an American author who made her literary debut with the psychological thriller *Nightwatching* (2024). The novel, which follows a mother's desperate attempt to protect her children during a home invasion, showcases Sierra's talent for crafting intense, claustrophobic narratives centered on maternal instinct and survival. Her writing is characterized by its propulsive pacing and exploration of primal fears surrounding family and safety. *Nightwatching* received significant acclaim, becoming a Reese's Book Club pick and earning praise for its gripping, atmospheric storytelling. Sierra writes in the thriller and suspense genres, focusing on the psychological dimensions of threat and protection.