- "The tears of Lys, a rare and costly poison. Clear, tasteless and odorless. Dissolved in wine or water, it eats at a man's bowels. He dies in agony. Which will not appear unusual if the victim is old and sickly. A favorite tool of impatient heirs."
- ―Oberyn Martell
In the books
In the A Song of Ice and Fire novels, the tears of Lys are apparently made in the Free City of Lys. It is tasteless and odorless, hence easier to hide. Dissolved in wine or water, it causes extreme sickness in the bowels and belly, and kills very quickly. Not only is it difficult for the intended target to detect, its effects are subtle enough that they are easily mistaken for a very sudden and severe fever. Even upon examination of the corpse, it is difficult to discern if someone has been killed using tears of Lys.