This chapter considers Michael Field’s collaborative authorship, focusing on the tension between singularity and plurality in their shared authorial identity. It explores Michael Field’s pseudonymous collaboration as a constant negotiation between multiple voices that radically revises conceptions of both life-writing and verse in the nineteenth and early twentieth centuries. The chapter surveys Katharine Bradley and Edith Cooper’s shared diary Works and Days and their poems, such as ‘A girl’ to show how they generate a sense of unison in their work, in the process achieving a fluid negotiation between different voices.