In 1947, Englishman Reginald Cruise-Wilkins, a neighbour of Mrs. Savy, studied the documents, but the cryptogram was much more difficult to solve than first believed. Cruise-Wilkins' early writing indicates that the code may be based on Masonic symbolism. Cruise-Wilkins claimed to have discovered a connection with the Zodiac, the Clavicles of Solomon, and the Twelve Labours of Hercules. Various tasks, representing the Labours of Hercules, had to be undertaken in strict order. The treasure chamber is somewhere underground and must be approached carefully, to avoid being flooded. It is protected by the tides, which requires damming to hold them back, and is to be approached from the north.