In the womb-dark of the first new moon following the Winter Solstice, most Black Furies take part in what they term the Mysteries. The Mysteries, as do all widespread rites, vary from sept to sept, but the essential nature and pattern of this rite is surprisingly regular and unchanging. The new moon is a time of death, renewal and questioning. During the Mysteries, the Furies ceremoniously make their way (if possible) to a selected tor with a cave in it or a tree on top. Once at the tor, the Furies beyond childbearing age each in turn unwind a black string and tie it around the tree or a rock placed in the center of the cave. The Furies who have borne children then take their turn, tying red twine aroudn the tree or stone. Finally, the young Furies tie lengths of whitecord around the central object.
The Ritemaster, usually the eldest in the gathering, then tells a tale of one of the many women who walked the spiral path into the labyrinth, into the death-darkness where knolwedge lies, perhaps into the arms of the enemy. There are many such heroines: Persephone, Inanna, Kore. As she speaks, one by one the Furies begin a dance, often mimicked by maypole revelers, during which each Fury weaves her thread among her sisters as she makes her way down the spiral path. When they have finished their dance and the ritemaster has ended her tale, the sisters sit in the darkness and share a cup of blood-wine, the drink of spiritual awakenings. Until recently, a touch of hemlock or other poison was always added to the brew to aid in visions, but the dangerous process is not always practiced today. The rite ends at dawn.
Source: Werewolf Storytellers' Handbook