Wootz

Wootz is steel with the property of currents in its pattern: sabers and garb made of it set alight, slow, heal or guard against lava. Brew Alloy, Lattice and Fray in equal measure in a Crucible on strong heat — the Poles argue, and that is where the pattern comes from — and add any currents you like. Throw in a brightsteel ingot: it will not float up but lie on the bottom. Take the heat away, and the Crucible cools for a minute.

AlloyLatticeFray

Cooled, the Crucible gives up a wootz ingot: the pattern of the two strongest remaining currents shows on it, and all the distillate goes into the ingot, without murk. Touch the cooling Crucible — throw something in, bring the heat back — and the ingot turns to slag and the distillate to murk.

The pattern works as a faint weaving of its currents: Ember sets alight, Tide quickens in water, Rime slows, Bloom heals, Venom poisons, Fray strikes past armor. A thing of wootz takes the pattern of its ingots only if they all share it; different patterns or a plain ingot give motley wootz with no property. In a chunk where murk is above a third of the bed, the pattern goes dull. Next: "The Wootz Retort", "The Wellspring", "Wootz Saber" and "Wootz Garb".