Why were there no extradition treaties between China and most Western countries historically? Jenny Huangfu Day traces how the fugitive rendition clauses in the Opium War treaties evolved into informal extradition practices and argues that China’s inability to secure reciprocal extradition treaties was rooted in the legacy of extraterritoriality and semi-colonialism. Through an examination of a series of landmark but often overlooked extradition cases between China and foreign powers — especially between Canton and the colonial government of Hong Kong — she challenges the notion that “political crimes” in modern China emerged solely as a domestic legal construct, instead situating them in transborder legal and diplomatic processes open to interpretation and maneuvering by both state authorities and the broader transborder population.