Book excerpt: Michelle Peterie’s revealing research offers a fresh angle on the human costs of immigration detention. Drawing on over 70 interviews with regular visitors to Australia’s onshore immigration detention facilities, Peterie paints a unique and vivid picture of these carceral spaces. The book contrasts the care and friendship exchanged between detainees and visitors with the isolation and despair that is generated and weaponised through institutional life. It shows how visitors become targets of institutional control, and theorises the harm detention imposes beyond the detainee. As the first research in this area, this book bears important witness to Australia’s onshore immigration detention system, and offers internationally relevant insights on immigration, deterrence and the politics of solidarity.