The other, pressed against the masonry, conceals a cross design that nobody standing in front of the church can see. That hidden face exists, has been recorded, and continues to carry its carved geometry in the dark.

The slab began its life not at Raheen but on High Island, a small and remote island off the Connemara coast with a well-documented early Christian monastic site. It is one of three decorated cross-slabs associated with a single grave, known as Grave 3, and scholars have suggested it may predate the construction of the church itself, belonging to an earlier phase of burial activity on the site. At some point the slab was removed from High Island and brought to Raheen, where it was built into the external face of the east wall of the church, serving as a headstone. The slab is just under a metre tall and roughly 39 centimetres wide, cut from garnet mica-schist, a stone with a faintly sparkling quality. The visible east face bears a cross-head decorated with three incised circles arranged as a double roundel, a concentric ring motif found on early medieval Irish carved stonework. The concealed west face, recorded by White Marshall and Rourke in 2000 and later by Fisher in 2014, is more elaborate: a cross with expanded arms and sunken armpits, with a central double roundel enclosing a linear Greek cross laid over an outline Greek cross whose arms flare outward at the tips. The two designs, one face turned to the world and one sealed against a wall, together suggest a carver working through variations on the same devotional geometry.