Eddy looked better at the last picture. It was dark and only a few blue and purple marks, rendered phosphorescent by the scientific lamps, stood out against the wood. The signs formed a frowning human face. It was a strange image; it even seemed to be drawn by a child but had clear contours, almost as if it were a puzzle card. On the painting instead a writing was impressed. It was hardly read but there were no doubts: «Cave. Cave Deus Videt.»
«But how is it possible that this masterpiece has escaped you?»
«It didn’t escape us. In reality latent fingerprints are more difficult to grasp. We used fluorescent lamps.» Marco indicated with a movement of his head the shelf behind the inspector, where the small lamp was resting. «They've just arrived from Finland. With those you can graduate th
