Dark-fire wood
Unlit wood cut out of the Twisted Grove's death-tree, which takes the life out of a bare hand and lights only from ordinary flame
Cut unlit out of the death-tree at the Twisted Grove in the days after the curse there broke, and carried four days south to Loshev.
Getting it was its own problem. A torch held to the burning tree will not take light off it, and a branch will only break away if you stand in the cold coming off the trunk long enough to commit to the work, which costs you some of your life to do. Burning material could not be moved at all, so what came away was unlit wood, on the understanding that the fire could be made from it later. It can: a piece lit with ordinary flint and steel burns like ordinary wood for a heartbeat, snuffs, and comes back as dark fire.
Unlit, it still drains a bare hand closed around it. It was handled in short bursts, or at the end of a mage hand, and then packed into the lead-lined box and folded into the Oubliette, where the draining stopped altogether. Extradimensional storage takes the drain away entirely, and the cloak itself is untouched by it, having no life in it to take.
Hinta wanted it, and wants it still, for what a forge might do with it.