In the highly contentious abortion arena, the new oral abortifacient technology RU486 is one among many actors. This article offers an arena analysis of the heterogeneous constructions of RU486 by various actors, including scientists, pharmaceutical compa nies, medical groups, antiabortion groups, women's health movement groups, and others who have produced situated knowledges. Conceptually, we find not only that the identity of the nonhuman actor-RU486 -is unstable and multiple but also that, in practice, there are other implicated actors—the downstream users and (...) consumers of the technology. If we try to follow all the actors, we find a fuller and more historicized arena, and, ironically, we too can be construed as implicated actors in it. (shrink)