How to identify rules of customary international law? According to legal doctrine, customary rules arise out of a general practice that gets accepted as law. In other words: to identify a rule of customary law is to identify a history, a pathway that led up to this or that particular rule. If there is controversy about the validity or content of a rule of customary international law, this typically revolves around the identification of such pathways. Pathways need to be constructed through stories that highlight certain events and downplay others. In our chapter, we illustrate the relation between story-telling, pathways and the identification of customary rules through a topical example: the struggle between the African Union and the ICC about the immunity of heads of State. Through a close reading of the arguments presented before and by the Court, we show how the construction of different pathways results in opposite readings of the customary rules on immunity.