It is described that Dagwood "failed to realize" that a mysterious sound was coming from the mine (possibly the Gracq mine) even after electric equipment had been turned off. Therefore, the buzzing was of natural origin. The solution to this was to keep digging, which meant that museum authorities found shovels and notebooks the next morning.
It is said that a key was in the cobblestones, which could be pushed aside by small plants and therefore wouldn't hold up against violent animal life. Both Dagwood and Violetta would have known this from their father, a geologist and former travel agent who had lived in the same neighborhood.
- Only the conclusions to the suspicious incidents involving Dagwood are listed, meaning that much of Dagwood's history is unclear.