The Crown of Horns was, as Fone Bone described it, "a wall." It glowed with extreme brightness and appeared to be made of jagged crystal.
The early history of the Crown of Horns, like most information about it, is sketchy. It is unknown whether it was in existence before the Dragon's first war against the Locust or whether it appeared later on. It became the Dragon's greatest secret and has become in Dreaming lore a sacred object.
While Thorn and Fone Bone were in a ghost circle, a projection of Thorn's mother gave the message to Seek the Crown of Horns.
During the seige of Atheia, Thorn discovered from Phoney Bone the location of the Crown of Horns and was able to find a gap through the dense wall of ghost circles and Pawan soldeirs. She reached the Crown of Horns but was stopped by Kingdok from touching it. Fone Bone was later able to draw from her the power of the Locust and use the Crown of Horns to destroy the Locust. It then collapsed with the rest of Tanen Gard.
According to the Dreaming Master, the Crown of Horns sits directly upon the Veil, halfway between the worlds of Dreaming and our world. It is a sort of tipping point on which balance rests on. It was conjectured that the force of the Locust would destroy the whole of existence, yet Thorn proved that it was not only able to destroy the Locust but also dissolve the ghost circles, disband the Rat Creatures, and quicken the healing process. However, the force seems to have destroyed it in the process.