In 1870, Hughes created a device capable of sending and receiving electromagnetic transmissions. To his surprise, his device was receiving signals the moment it was turned on.
After seven fruitless years of research, Hughes consulted a friend and discovered the same pattern he had been receiving carved into stone tablets from Mayan temples dating back to the first centuries CE.
Following further research and decoding, Hughes told his friends and colleagues that he would have a spectacular announcement to make. Unfortunately, he died three days before his announcement was to have been made. All references to the mysterious signals were removed from his notes and records by his attorney, as commanded in his recently-altered will. The only remaining reference was in the final pages of his diary:
"Long and painful hours, months, years, have brought me to this, but a small fraction of a greater whole, made finally clear to my understanding. And yet these few words, I cannot bear to hear. Let them reach no other ears. Let what is fallen remain fallen."
It's not made clear in the book, but it's likely that David Hughes refers to David E. Hughes, a Welsh musician who is notable for having invented the type printing telegraph and the microphone. Although he recognized the potential value of the microphone, rather than get rich by patenting it, he released it to be used and developed by anyone.