The British police has become a more controversial institution over the last 30 years, during which period the interest of social scientists in the nature of policing has intensified accordingly. As knowledge has accumulated, researchers have increasingly sought to influence the policy-making process through their findings and recommendations. One aspect of policework which remains poorly understood, yet whose illumination is crucial to the success of these efforts, is the process whereby policy is implemented within the organisation. This study addresses this issue through an analysis of relations of power and influence within four Scottish Divisions. Attention is centred upon the main 'line' organisation connecting uniform patrol to the divisional hierarchy, and in particular, upon the role of the patrol sergeant as a crucial intermediary rank. It is argued that, against a background of an indeterminate mandate and a rigid bureaucratic framework, recent changes in public attitu des and expectations, in the political and legal environment of policing, in its organisational and task structures, and in police officers' orientations to work and authority, have eroded the basis for consensus between ranks and exacerbated mutually instrumental attitudes. This more instrumental climate is self-perpetuating, frustrating attempts at all levels to maintain or re-establish harmonious relations. For the sergeant, these problems emerge as a set of strategic and existential dilemmas which requires them to manipulate a declining resource, namely trust, in balancing the demands of seniors for effective and legitimate performance, and those of juniors for feasible working targets and protection of operational discretion. Sergeants employ many devices to this end, with only limited success. The transformation of inter-rank relations such as to reconcile these aspirations requires instead a broader package of reform measures, with the restructuring of the system of police accountability as its centrepiece.