On Clinical Interventions addresses the task of the analyst in family therapy, and the gradual joint development of the clinical device in the immanence of the session. We describe the progress of a family treatment as a way of discussing the specificities of link therapy. We argue that: “The heterogeneity of the resources used in link analysis significantly enlarges the scope of analyzable cases and opens new fields for psychoanalysis. Our willingness to make room for and legitimate these fields in their different variants is unavoidable. In each case, our clinical practice involves designing a device and setting it in motion. The type of device we choose is already a form of intervention.”