Through collaborative autoethnography, we studied shifts in cancer patients’ sense of agency and the meaning of cancer during the diagnostic and treatment phases. This article contributes to the illness management literature by adopting sense of agency perspective that provides new understanding of retrospective interpretation of cancer patients’ agency. The authors’ experiences of receiving cancer diagnoses and a related, collectively written story illustrate how relational and contextual elements facilitate rapid shifts in cancer patients’ sense of agency and illness management. The findings illustrate shifts in the sense of agency as a collaborative and reflexive process between cognitive, emotional, and bodily constraints and adjustments. We demonstrate how shifts in patients’ sense of agency and respective changes in meanings attached to cancer were shaped by near ones, healthcare actors, and other cancer patients, as well as the COVID-19 pandemic and the fear of military conflict due to Finland neighbor Russia’s war on Ukraine. Furthermore, the study illustrates how shifts in sense of agency shape and are shaped by changes in the understanding of cancer as either a secondary issue, ambiguous stranger, travel companion, or enemy.