On the bottom shelf behind a row of salves in squat clay jars he found a vial of indigo glass, no larger than his little finger. It rattled when he shook it. Cressen blew away a layer of dust and carried it back to his table. Collapsing into his chair, he pulled the stopper and spilled out the vial's contents. A dozen crystals, no larger than seeds, rattled across the parchment he'd been reading. They shone like jewels in the candlelight, so purple that the maester found himself thinking that he had never truly seen the color before.

The chain around his throat felt very heavy. He touched one of the crystals lightly with the tip of his little finger. Such a small thing to hold the power of life and death. It was made from a certain plant that grew only on the islands of the Jade Sea, half a world away. The leaves had to be aged, and soaked in a wash of limes and sugar water and certain rare spices from the Summer Isles. Afterward they could be discarded, but the potion must be thickened with ash and allowed to crystallize. The process was slow and difficult, the necessaries costly and hard to acquire. The alchemists of Lys knew the way of it, though, and the Faceless Men of Braavos... and the maesters of his order as well, though it was not something talked about beyond the walls of the Citadel.