Castlepook’s modified reindeer femur is compelling because it may preserve evidence of a brief human encounter with Ice Age Ireland, yet its disturbed cave context prevents that encounter becoming a narrative of permanent settlement. The article carefully separates possible animal processing from assumptions about population continuity, arrival routes, or daily life. This invites comparison with better documented Palaeolithic sites elsewhere in Europe: how far can models of mobility, seasonal hunting, and stone-tool use illuminate Ireland without being imposed upon its exceptionally sparse record? What combination of direct dating, taphonomic analysis, and excavation might distinguish a single incursion from repeated visits?