Our knowledge of how to design innovation ecosystems that effectively deal with grand challenges or wicked problems is currently insufficient due to a lack of understanding of their joint innovation processes. Through the use of an in-depth case of an innovation ecosystem designed to combat organized crime, this study shows how diverse government authorities manoeuvre innovation and interact to continuously make the challenge amenable and identify and implement provisional and innovative solutions. Drawing on extensive data gathered from observations, documentation, and interviews with multiple stakeholders, we contribute to the innovation ecosystem literature by offering a model of three interdependent and complementary innovation processes: responsive, preventive, and tactical innovation, supporting an ongoing and distributed experimentation among diverse actors. Furthermore, we emphasize the use of a hybrid interorganizational structure that combines hierarchical and horizontal structures, over one that is entirely network-based, and we highlight the crucial role of a focal collective actor as opposed to a single orchestrator of the ecosystem. Finally, the study suggests attention not only to strengths and complementary attributes but also to vulnerabilities and gaps between involved actors, providing unique innovation opportunities. The paper offers valuable guidance to designers and coordinators of innovation ecosystems addressing grand challenges.