This project explores the entangled relationship between knowledge, power, and material culture through the case study of a ceremonial beetle headdress (Mormah) from Simbu Province, Papua New Guinea, currently held in the Linden Museum in Stuttgart. The Mormah, once used during highland rituals such as Buka Ingu, exemplifies how colonial collecting practices decontextualized culturally significant objects, transforming them from living ceremonial regalia into static museum artifacts. Drawing on postcolonial theory and Donna Haraway’s concept of “situated knowledges,” the authors adopt a collaborative, decolonial methodology that brings together archival provenance research and oral history interviews conducted in the Kuman language with a key cultural informant—co-author Clara Bal’s grandmother. This interdisciplinary and transnational research design highlights the epistemic authority of insider knowledge and the ethical imperative of trust-based engagement. By analyzing the symbolic, ecological, and ceremonial meanings of the Mormah, the article foregrounds the object’s role within Indigenous systems of memory and social reproduction. The authors argue for a reorientation of museum practice that goes beyond provenance as property tracing, toward provenance as a relational, ethical, and political project. Through this approach, the Mormah becomes a site of cultural resilience and epistemic repair, offering new pathways for restitution, reinterpretation, and collaborative knowledge production between museums and source communities.