Before he met Charity Sullivan, Matthew Algernon Shannon, a.k.a. the Great Mysteros, was a retired sideshow illusionist who had taken up residence on a rambling estate to the south of Shrouded Hollows. A generous man, he frequently opened his doors to friends and acquaintances from his circus days who needed somewhere to stay, and even established a small cemetery on his property so he could house those who had nowhere to go after death. Shannon was not, however, a man of faith, at least not where many of the beliefs of the day were concerned, and Spiritualism in particular drew his prodigious wrath. Though retired, Shannon still traveled frequently and did what he could to debunk mediums wherever he went.

And then he managed to secure an audience with his adopted hometown's own local medium, and though he tried his best, the master illusionist could not find the slightest evidence of fraud in her practices or the manifestations she produced. Reportedly, Charity even put him in contact with figures from his own past, figures that Shannon himself had not mentioned, and revealed secrets known only to the illusionist and his late friends. Though Shannon continued to debunk fraudulent mediums and magicians, he developed a healthy respect, a sense of fierce loyalty and a strong faith in Charity herself, eventually joining the society that was rapidly forming around her. His faith was such that when the word came from Charity that Shrouded Hollows was to become a city of the dead, the illusionist promptly donated all the rest of his land to the cause, vastly expanding the existing cemetery. He continued to live inside his own rambling mansion, but only in order to convert it into a vast tomb for his own eventual use. It is said that Charity predicted his pending demise at the same time she delivered the revelation regarding the transformation of Shrouded Hollows, and just six years later, in 1904, she was proven right.

Like MacGillivray's Hollow, Shannon's Hollow Cemetery sits on a good deal of marshy land, and as such, the plots are used exclusively for above-ground tombs. Most of these are simple in origin; while he still lived, Shannon personally subsidized internment at his cemetery, and a blind trust managed to carry this practice on for a few years after his death, but eventually, the money ran out, and those who purchased plots at Shannon's Hollow were left to pay for their own memorials. Still, the older tombs are fairly elaborate and popular as homes for the undead.

As for Shannon's own home, per his instructions, it has become his memorial. The man himself is interred somewhere deep within its walls, but the house contains so many secret doors, illusions and traps that no visitor to the site has ever managed even to escape the foyer. That doesn't keep people from trying, of course; none of the traps encountered thus far have been lethal or have prevented visitors from leaving the house in peace when they fail, and naturally, countless rumors claim that great treasures may be found somewhere within the house, perhaps within the burial chamber proper. Fortunately, the design of the house is so fiendishly clever that, whatever the truth, the tomb has not yet been spoiled.