Since Kahn's (1990) pioneering work, the concept of engagement has attracted considerable interest globally. With expansion is a desire for conceptual convergence. Yet different disciplines (work psychology, HRM/D, industrial/employee relations), theoretical approaches (unitarism and pluralism) and research methods (positivist/quantitative and interpretivist/qualitative) create divergence. I consider the life-cycle of engagement, as an ‘umbrella’ construct, to make sense of convergence and divergence in HRD. Kahn advocated multi-level, case study research to better understand engagement yet this has been overshadowed by a dominant narrow, unitarist and quantitative perspective. To explore tensions between diverse conceptualisations, I conducted a narrative review. This identified theoretical, methodological and practical implications of unitarist and pluralist perspectives. I argue engagement needs to be conceptualised from a critical HR, pluralist perspective, and present a multi-level analytical framework to assist this endeavour. I propose a new direction for engagement research. This more situationally-sensitive, employee-centred approach recognises discretionary behaviours flow from the competency of HR(D) practitioners and line managers in balancing efficiency, equity and voice within the contested work context. Such a critical HR/pluralist approach might address some of the criticisms charged at HRD professionals of being removed from work-place realities.