Since the 1990s, recognition has grown that the answer to corruption --political, bureaucratic or corporate-- does not lie in a single institution, let alone a single law. Rather the institutionalisation of integrity through a number of agencies, laws, practices and ethical codes is increasingly recognised as the best option for limiting corruption in many societies. This article addresses the key issue of coherence between these various institutions, picking up on the third and final theme of the Australian national integrity system assessment. The assessment has shown, firstly, that concepts of 'horizontal' or 'mutual' accountability are important but also need to be developed and better contextualised as a framework for designing integrity systems; secondly, that integrity system coherence can be usefully measured and mapped using standard network analysis approaches, helping more clearly identify the need for more deliberate strategies for coordination of integrity policies; and thirdly, that new metaphors can and should be developed for communicating the nature and significance of the institutional interactions that constitute integrity systems. The new metaphor suggested here is that of a bird's nest, in which a multitude of often weak institutions and relationships can combine to more effectively protect and promote the fragile goal of public integrity.