Setting out from interactions experienced throughout four years of field work studies, I focus on a therapeutic ritual involving ayahuasca consumption led by two young Kaxinawá shamans. The article undertakes the discussion of the equivocal compatibilities that make possible the interaction between Amerindians and non-Amerindians in this context. Citing a number of interactive contexts beyond the rite's space-time axis, the text explores the sense of mutual understanding that occurs thanks to a 'synonymous effect'. This effect places spirits and mythological beings, for example, on the same psychological and sentimental level, creating a metaphorical continuum between those involved in the communication. Ethnographic data suggests that urban Nixi Pae rites explore the equivocal compatibility between two terms that give rise to this communication context: Yube and the unconscious.