Detention can take various forms, but the deprivation of liberty inevitably carries costs that fall on the detainee, their family and the community at large. These costs, both individual and collective, are often linked to other, financial costs that authorities are unwilling to incur on behalf of a group of people who are out of sight. This short-termist calculation has serious implications for prisoners today, and for our societies in the future. Objectively assessing the human, social, political and financial costs of detention policies is essential to avoid detention becoming part of the problem it was meant to solve. In this edition, the Review takes stock of developments in detention practices and policies, and focuses on a range of challenges related to maintaining human dignity in detention, including overcrowding and aging prison populations. In drawing attention to the ongoing challenges associated with detention, the Review seeks to promote the human dignity of detainees.