The Psy-Changeling Series is a popular paranormal romance series written by author Nalini Singh. Set in a world where three distinct groups coexist—the Psy, who possess psychic abilities; the Changelings, shapeshifters with animal traits; and humans—the series explores themes of love, identity, and societal conflict. Each book typically focuses on a different couple, intertwining their personal stories with larger plot arcs involving the dynamics between these groups. The series begins with the novel Slave to Sensation, introducing readers to the complex relationships and tensions among the Psy, Changelings, and humans. As the series progresses, it delves deeper into the characters' backgrounds and the evolving world, featuring a rich cast that includes various Psy and Changeling characters. The blend of romance, suspense, and fantasy elements has garnered a dedicated fanbase.