Within the little known 'Century of Wonders' between 1848 and 1948 in America, the physical phenomena manifesting in the séance rooms of the great psychic mediums baffles description. Two of its most famous mediums and yet, most vilified by the conjurers and critics of that day, were the Bangs Sisters, May and Elizabeth, of Chicago. In their presence spirits of the departed would manifest and precipitate directly on to a blank canvas in front of the astonished witnesses and, equally wondrous, spirit writing would manifest directly on to blank sheets of paper or slates. The present work, by author and researcher N. Riley Heagerty, explores through rare source material and eyewitness accounts by people of unimpeachable character, the seemingly " miraculous " phenomena that was produced. In a fair and balanced manner, the writer also takes a close look at the most heated and public charges of fraud brought against these Chicago wonder workers. This in depth, complete work, the first of its kind, unravels the truth of the great psychic mystery of the Bangs Sisters.