This chapter analyzes some of the ethereal figures that populated the colonial imaginary in India during the nineteenth century, including thugs, pirates, and fanatics. While each of these figures had its own unique features, a significant degree of slippage and overlap can be found between them and – more importantly for the purposes of this study – in the legal and security measures adopted by the colonial authorities to contain them. Operations of ‘pacification’ undertaken with the goal of rooting out secretive groups of thugs, criminal tribes, pirates, or fanatics were typically directly linked to the project of establishing British sovereignty in and around the Indian subcontinent, by land and by sea. In this process, colonial administrators, judges, soldiers, police, and scholars produced, repurposed, and recycled a set of tropes portraying certain groups of Indian men as barbaric, violent, cowardly, secretive, or superstitious threats to colonial order.