A Small Booklet...Stitched Together With Red Thread

Orlando's Blood by Jacqueline Nichollshttp://www.jacquelinenicholls.com/
red-thread-drawings.html

A small booklet with dozens of square pages that have been stitched together with red thread, and then bound with resin. Each page is written in red ink, and describes a favor given to someone, or a favor owed to someone. 

The booklet is used to enforce reciprocity. 

The Bloodweaver Wizards who contended for dominance in the realm of Woven Strife created these books when they tired of constant broken promises and betrayals among their peers. These booklets brought a quick end to shifting alliances, and great predictability to the fulfillment of arrangements made between peers.

When you do someone a favor, you record the deed in the booklet. At the time, the beneficiary agrees to return you an equal favor in the future. It is understood a favor which will need to be reciprocated as soon as the original benefactor of the original favor calls in its return.

If someone reneges on a promise to reciprocate, then the book itself takes revenge. The ink and threads of the book swirl and form a shape. A tiny hand-high Red Swordsman comes forth from the book. It sets immediately to take a revenge of its own devising on the person who reneged on the favor. 

The Red Swordsmen are clever, tireless, and creative. They will observe and even secretly cohabit in the home of their target until they find and execute a fitting revenge. Their revenge is not always lethal. But when the deed is done, everyone will know that the target is someone who can't keep their end of a deal. 

Thysanurians find these favor-books particularly appetizing.