The article draws on our respective work on the transnational adoption files that ordered the movement of children from Guatemala to Europe in the latter part of the 20th century and up until 2007, to consider strategies to detect and figure the irregularities that underpinned these transnational adoption flows. We intersect approaches to deciphering the files drawn from anthropological research conducted in Guatemala, and in Europe in the context of work to support adoptees’ individual and collective search for origins. We provide an overview of the historical and political context, and the legal arrangements that underpinned the rise of transnational adoption flows from Guatemala (1977 – 2007). We consider how adoption files operate as entry points into searches for origins and understandings of the adoption process. When read against the grain, adoption files simultaneously reveal and occlude personal histories and bureaucratic practices. They evidence entrenched, varied and sometimes haphazard practices of forgery, omission and creation. Anomaly and incongruity in the files emerge as structing devices that reveal the operations of transnational adoption shadow circuits and counterfeiting as method. For those seeking historical clarification, deciphering forgeries and irregularities entails creating new registers of legibility of the adoption papers, the adoption process and the relationalities generated through their searches