The case of the Golden Beetle (Issue 5)

This whole story began with the fact that one eccentric professor picked up a parchment piece on the shore of the pirate bay to wrap his find in it - a golden beetle! The beetle is actually not gold, but golden, but on the back its drawing, resembling a human skull. Writing on the wall! Immediately after this find around the professor, an incomprehensible bustle began, as a result of which the scientist was accused of a serious crime.
Auguste Dupin, the best police inspector Boston, and I, his young partner, joined in the investigation with heat, because this harmless eccentric is an old friend of the inspector.
But it was I was the first to guess that the point was not in the beetle, but in the very patch of parchment ...
For secondary school age