This chapter shows how British sovereignty in Hong Kong was built on inchoate ideas of extradition: half-formed ideas of whether and how the colony would surrender Chinese criminals to China under the contested treaties that ended the Opium War. In 1841–44, these ideas were entangled with unstable ideas of jurisdiction, as British officials struggled to fit the conquered Chinese population of Hong Kong within recognised categories of British subjecthood. Events on the ground then short-circuited efforts to resolve this problem. In The Queen v. Lo A-tow (1843), Governor Henry Pottinger conflated his power to refuse Chinese requests for fugitives for lack of evidence (which China did not dispute) with the power of British courts to try Chinese subjects and sentence them to punishment (which China did dispute). Pottinger’s interpretation of Lo A-tow established a tenuous precedent for territorial sovereignty in a turn of events that would have far-reaching consequences.