I followed her down a flight of stone steps and into the main body of the chamber. We were in a huge basilica that must run the length of the rock buttress beneath the cross and whose ceiling was lost in gloom high above us. Up ahead was another set of steps, leading onto a raised and slightly narrower section where the lighting was stronger. As we reached it, I saw that the roof here was vaulted over the stone statues of hooded guardians, their hands resting on thick broadswords and their lips curled into faintly contemptuous smiles below their hoods.