The need for inter-organisational information systems projects, which are complex undertakings often riddled with poorly understood power struggles and conflicts that hinder project success, has increased in previous decades. Through the lenses of systemic and episodic power, together with an organisational conflict model, this longitudinal, qualitative case study explores the dynamics of power and conflict and their effects in an inter-organisational information systems development project. This study highlights that the bureaucratic, social and technical setup of the project forms a foundational system from which specific power practices emerge, in this case, the practices of hiding, storytelling and bargaining. The power practices have both restrictive and productive effects on conflict, but the practices cannot easily escape the confines of the foundational system and continue to cause the resurfacing of different manifestations of latent conflict inherent in the system. As a result, both ‘power to’ (systemic power) and ‘power over’ (episodic power) can escalate project conflict, and rational conflict management for gaining ‘win-win’ resolutions may not be in the stakeholders' interests. Thus, strategies for openly managing political conflicts should be considered.