This volume contains the contributions of the 21st Cross-Border Crime Colloquium webinar hosted by the Norwegian Police University College, Kongsvinger and organised 22-24 August 2021. Despite the pandemic, the Colloquium Group decided to return to the 'criminal normal' and the related research on (cross-border) organised crime, corruption, labour exploitation, fraud, ecological crime and the search for criminal revenues. These are partly old themes, some getting renewed attention, such as the hidden wealth of corrupt political elite, whether Nigerian godfathers or Russian oligarchs. A...