Draught of the Last Shadow

This thumb-sized vial is made from black glass that reflects no light. A silver stopper seals a swirling liquid darkness within, and a thin violet glimmer moves through it like a drowned constellation. The vial feels heavier than it should, as though it contains a pocket of night. When held near a flame, the flame bends toward it, and the holder's shadow reaches subtly in the vial's direction.