One of therapy's greatest challenges is the moment of transference, when a patient unconsciously transfers emotion or desire to a new and present object, in some cases the therapist. During the course of treatment, a patient's projections and the analyst's struggle to divert them can stress, distort, or contaminate the therapeutic relationship. It may lead to various forms of enactment, in which the therapist unconsciously colludes with the client in interpretation and treatment, or projective identification, in which the client imposes negative feelings and behaviors onto the therap.