Ogham
Tinne is an ingot, the kennings say: one of three parts of a weapon, the marrow of charcoal. It is refined metal, a component of something that has to work, and it is not the finished thing. This week you are one part of three. What you contribute has been refined, it is good, and on its own it is not a weapon. Find the other two parts and let the forging happen. The ingot that insists on being the whole sword ends up as a bar on a shelf, and the one that accepts being a third gets to cut.