- A littermate
- A cub raised alongside another from the start, taken or born, treated as blood in every way that matters to the pack.
- A pack
- Where the Bound live, hunt and raise their young. A pack that cannot hold its numbers does not disappear, it replenishes.
- A taken one
- A human child brought into a pack and made one of it. It is spoken of plainly, not as a wound: ask any den and half of it will tell you the same about itself.
- essence
- The inherited force that runs in the Bound's blood and nowhere else. It is where their magic comes from, and humans are born without it.
- hallowbound
- Taken and remade by the rite. A hallowbound child keeps the shape of the body they were born into and loses almost everything else of who they were before.
- The Bound
- What the Bound call themselves. To humans, the word is beasts; neither term is neutral, and nobody in a den much cares which one the surface prefers.
- The Rite
- Known outside the dens as the binding rite: the ceremony that takes a human child and grafts essence into them, binding them to a pack for good.
- The Undercity
- Home to the Bound: torchlit, built up and down rather than across, firelight against cold stone. People live here, cook here, and raise their young here.