Recent scholarship in genre studies has extended its focus from studying single genres to multiple genres, as well as how these genres interact with one another. This essay seeks to contribute to this growing scholarship by adding a new concept, "intermediary genre". That is, a genre that facilitates the "uptake" of a genre by another genre. This concept is designed to reveal a particular aspect of multiple genres: that one genre can be used to connect and mobilize two otherwise unconnected genres to make uptake possible. The concept is illustrated in case study of knowledge mobilization, an instance in which scientific research was used in the judicial system to inform public policies on eyewitness handling and police-lineup procedures. The case study shows how intermediary genres emerge, how they connect other genres, and how knowledge circulates as a result of such connections and affects policy decisions. (Contains 3 figures and 7 notes.)