A photograph depicts the anthropologist Franz Boas posing as an Indigenous youth in search of human flesh. It looks like an icon of cultural appropriation, but behind the picture is a history of Indigenous influence. The archive of body knowledge—memories encapsulated in the motions of dance and indexed in images—reveals that the Kwak’wala-speaking peoples civilized the white man who came to study them, converting him to the Host–Guest logic of “potlatch” encoded in their Hamatsa dance. Seeing Boas as a host body of Indigenous knowledge radically reconfigures our understanding of influence, compelling us to ask who creates modernity.