The Children of the Thorns are a group of vampires bound together by their experience with a shadowy figure called Bloody Mary.
Contacting Bloody Mary functions much like the children's game of the same name. A vampire stands before a large mirror in total darkness, and smears the glass with Vitae. After chanting the name "Bloody Mary" three times, they are able to step through the mirror.
At this point, they find themselves in a dark, weed-choked graveyard full of crumbling tombstones. In the center is a large mausoleum, undecorated except for the name MARY carved above the door. Walking away from the Crypt in any direction, the undergrowth thickens until it merges with the trees, creating a maze of thorny tunnels. The sun never rises in this place, and vampires do not have to make any effort to stay awake.
All Children of the Thorns have visited the Crypt at least once, although none speak about what they found there. A few become Oracles, who receive visions from Mary herself with instructions or prophecies. All Children recognize each other on sight, and have an attenuated version of the Predator's Taint: they are less likely to frenzy on sight of another Child, but more likely to frenzy around a vampire of any other covenant. This bond, and the words of the Oracles, is what makes the covenant run.
The same mirror ritual will transport the user, and up to two "passengers," to Mary's graveyard. The darkness must be absolute, and the mirror must be doorway-sized. The ritual will work with cracked or damaged mirrors, but passing through such a portal deals damage to the travelers.
The bigger issue is how to get back out again. The passages leading away from the graveyard are lightless and twisting, and some who venture out into them never return. Others eventually find themselves emerging back in the real world--for some reason the most common point of egress is Cape Town, South Africa, but one could end up almost anywhere. Still others claim they dared the paths and found themselves in some other world entirely, under alien constellations.
A more reliable means of getting out of the graveyard is called a Crypt Rendezvous. The mirror ritual creates a visible portal in the graveyard, and someone who jumps into one can switch places with the inbound traveler. There is even a brief window in which the two can speak before passing through, so the outbound traveler knows where they're about to end up. Children planning a trip to the Crypt will make arrangements with another Child, to ensure that a portal to the right place will open at the right time. In this fashion, the graveyard serves as an extra-dimensional shortcut that allows Children to travel nearly instantly anywhere in the world...assuming that nothing interrupts the rendezvous.
Connections with Changeling: The Lost
None of the Children truly know what Mary is or what she wants, although they may have their guesses. The thorny maze surrounding the graveyard suggests that it may exist somewhere in the Hedge, which might mean Mary has a connection to the True Fae. While vampires cannot become changelings, there is no telling what Glamour-infused blood might do to them; another option is that the Children are Vitae-smeared Fetches sent by Mary to enact some plan outside the Hedge.
Carthian Movement · Circle of the Crone · Invictus · Lancea Sanctum · Ordo Dracul