Rafael Lozano-Hemmer's installations engage the audience in unique and seductive ways-measuring their heart rate, surveilling their faces, even circulating their breath. Often characterised by particular interactions between the work and the viewer, Lozano-Hemmer's art explores themes such as forced cohabitations, power imbalances, and contemporary techniques of surveillance and control. This mid-career retrospective book focuses on works produced over the past two decades. It includes essays that explore the poetic and political dimensions of the artist's work, along with in-depth examinations of four major works-Zoom Pavilion, Vicious Circular Breathing, Voz Alta, and Pulse Room. It also features full-colour illustrations of sixteen recent works, including a newly created immersive sound environment, Sphere Packing: Bach. An essential guide to a deeper understanding of the themes that connect these technically sophisticated and emotionally resonant works, this book draws on the idea of an "unstable presence" to communicate the humanity and the anxiety that lie at the centre of Lozano-Hemmer's art.