Item from Bride by Ali Hazelwood
The interspecies political arrangement that trades people — usually women — as living guarantees of peace, wrapping hostage exchange in the language of marriage and diplomacy.
The Collateral system is the mechanism that keeps the three species from open war — and the mechanism that chewed up Misery Lark and spit her into a werewolf's bed. It works on a simple principle: if each species holds someone the other side values, nobody starts a fight. In practice, it's a formalized hostage exchange dressed up in wedding clothes. The system has kept the peace for centuries, which makes it very hard to argue against even when you're the one being traded. Misery's marriage to Lowe is the latest iteration — a Vampyre councilman's daughter sent to the Were Alpha as proof of good faith. That neither the bride nor the groom had any say in the arrangement is considered a feature, not a bug.
The Collateral system has no physical form — it exists as a set of treaties, protocols, and centuries of precedent. Its manifestation is in the people it moves: the Vampyres sent to Were packs, the Weres sent to Vampyre territories, the individuals who become political symbols rather than people.
Also known as: The Collateral, Collateral Marriage, The Alliance System