We were allowed no privacy; the police officers were present in the room and able to overhear everything. The officers, though, appeared to be totally disinterested in what we were doing, passing their time either watching TV or drinking their coffees and chatting noisily. In any case, it is not as if we could have had a proper conversation with the men we were ‘screening’, as we did not have any interpreters with us and instead had to rely on a mixture of sign language, Greek, English and whatever words in Urdu we had learned thus far. We are not police, we said. But we were in a room full of police officers. We are here to help you, we added. But in fact, we were unable to provide them with anything of use, neither information about their cases nor essential (hygiene) items the police did not offer. In a few days, we had completed our task and delivered the paperwork to the NGO offices, for use as evidence to funders and the authorities for the ‘support’ offered. In this case, NGO Arogos acted as an intermediary between the state and those behind bars by registering around 2.000 detained persons that the police were unable or unwilling to do so. Yet its role and interests in doing so and the power inherent in acting this way are opaque and should be subject to critical examination (Choudry and Kapoor, 2013). This experience, in fact, led me to question the ability of NGOs to do good without doing wrong (Fisher, 1997); hence, I opened with this story as an illustrative example of the collusions, complicities and entanglements between the police and non-state actors that the discussion here focuses on. In this chapter, I examine the role of non-state actors, with a particular focus on nongovernmental organisations, in shaping the practice of detention in Greece. My main goal is to unearth the perspectives of different actors inside detention, the challenges and struggles they encounter and the strategies they adopt to navigate the intricacies of life in detention. Building on scholarship in critical humanitarianism (Agier, 2011; Fassin, 2012; Feldman and Ticktin, 2012; Hyndman, 2000; Pallister-Wilkins, 2015; 2020; 2021) I argue, that there is a clash between non state actors’ moral and ethical drive to relieve suffering, and the constraints of operating in constrained circumstances. What is more, humanitarian interventions inside detention as they have developed over time in Greece, allowed detention to go unchallenged and also to thrive, often delivering discriminatory and violent consequences for those they purported to save. The chapter is informed by my experiences as a researcher and NGO practitioner from 2011-2013 and from 2016 up until now; thus, reflecting upon my own understandings, at 153