Piwi-interacting RNAs (piRNAs) are essential to repress transposable elements in the animal germline. In the nematode worm C. elegans, piRNA biogenesis requires a protein complex called PETISCO, but exactly what PETISCO does and how it works is poorly understood. The group of Sebastian Falk and their collaborators now provide unique insights into the molecular details of piRNA processing in C. elegans. PETISCO also has a second, unknown function in embryogenesis, which is dependent on the binding of a different accessory protein. The work resolves the question of how one protein complex can fulfill two different functions and is expected to help elucidate the elusive role of PETISCO in early development. The study is published in Genes & Development.