If it’s true that all family carry on a part of our story, it’s possible to use ourselves as an instrument of other’s knowledge. This work is inspired by the analysis of a clinical case about a family who lives the experience of conjugal separation and ask a therapy for the first daughter’s symptomatology. The examination is realized through some reflections about isomorphism between family and therapeutic system and the finally growth of both systems. The "monster’s visions", one patient’s symptom, become the "fil rouge" of the therapy, exemplify the importance of other’s acknowledgement and needs, through the use of therapeutic self and his own life experiences, above all through therapeutic resonances.
Keywords: Isomorphism, therapeutic relationship, separation, triangulation