Baptism and purgatory mark two entrances in the journey of a single self. The first, through water, opens the temporal succession; the second, through fire, opens eternal life. Drawing on the Gaitan Topology, this essay interprets both as threshold operations in the transformation of the same continuous person. The first sin and original sin are examined as one structural reality under two descriptions: in Lucifer an origin, in humanity an inheritance, and in both the same stance—“I am the cente