The paper proposes five stages through which such cases routinely progress: interagency cross referral, joint case conference, allocation of treatment responsibilities, simultaneous treatment, and formal joint periodic reassessment. It argues that the problems at these five stages are major contributors to treatment breakdown. The clinician who analyzes the dynamics at each stage is better equipped to control the treatment process than the clinician who restricts his or her attention to dynamics that are occurring within one agency. 1 figure, 15 references. (Author abstract)