Every animal contains in their genome pieces of DNA called Hox genes. Architects of the body, these genes are keepers of the body’s blueprints. Scientists have long searched for a key to decoding this body map. Now researchers have found one such key: a method that can systematically identify the role each Hox gene plays in a developing fruit fly. Their results offer a new path forward for researchers hoping to make sense of a process that is equal parts chaotic and precise.