This case study addresses the invasion of lionfish, a native to coral reefs in the tropical waters of the South Pacific and Indian Oceans, to the Alantic Ocean off the southeastern United States. The study explains how scientists are using newly collected data and technology to learn how an invasive species like the lionfish affects an ecosystem. Students can learn about the environmental and economic consequences of invasive species using the recent invasion of the lionfish as a case study. Supporting resources include student and teacher guides, interactive quizzes, exercises with real data, and interviews with National Ocean Service scientists that explore how scientists think. In addition, an instructor section provides materials and resources for use in the classroom.