Pius XI's encyclical references and confirms "Arcanum" (1880) on Christian marriage by Pope Leo XIII. The Terra Arcanum is an esoteric society dedicated to keeping the Hollow Earth a secret. Each text embodies a unique recension of a specific arcanum of the Crooked Path. Renault said the name derives from the Latin "arcanum", meaning secret. A Raptor is techno-mystical in nature, being versed in some forms of arcanum and magic. They have locations in Greenville, Arcanum, Versailles, and Ft. Castillo grew up in Arcanum, Ohio. Russell was fond of involvement in fraternal benefit societies, especially the Royal Arcanum. The structure of the Royal Arcanum follows a three tiered system. The Royal Arcanum home office is located in Boston, Massachusetts. For their eighth album, "Arcanum" (1996), the band re-recorded some of its popular tracks. The first book to be produced by Arcanum Worlds is "Odyssey of the Dragonlords". In 2012, the rights to "The Arcanum" were purchased by K. David Ladage. He called this the "Arcanum AZF". The Arcanum is a 2005 novel by Thomas Wheeler.