Eritrean refugees are being trafficked and enslaved in Libya, where they are tortured to force relatives to pay a ransom for their release. Labelled with a digital code, they are moved along in the possession of the traffickers through a series of 'black holes', in which their access to digital technologies and connectivity is highly controlled. They are tortured, abused, extorted and subjected to sexual violence. Many die along the way. If they make it to the Mediterranean Sea, they risk being intercepted and returned to Libya or dying at sea. Over the period of this study (2017-21), it is conservatively estimated that at least 200,000 men, women and children have fallen victim to human trafficking for ransom in Libya, and the cumulative value of this trade for that period is estimated at over 1 billion USD. This detailed ethnographic study identifies the routes, modus operandi, organisation, and key actors involved in the human trafficking for ransom of refugees and migrants, who are desperately in need of protection. The book is part of the GAIC Research Network and African studies series published by Langaa RPCIG and makes an important contribution to the literature on human trafficking, migration studies, African studies, modern slavery, social protection and governance. Mirjam van Reisen is Professor and the Chair International Relations, Innovation and Care at Tilburg University and the Chair FAIR Data Science at Leiden University. Munyaradzi Mawere is Professor Extraordinarius of Interdisciplinary Research at Unisa. He is also a full Professor of African studies and Research Chair at Great Zimbabwe University. Klara Smits is a PhD Student at Tilburg University, who specialises in Human Trafficking Trajectories from Eritrea to Libya. Morgane Wirtz is a PhD student at Tilburg University, studying human trafficking and sexual violence in Libya.