From A Wiki of Ice and Fire
The Treasure was a Braavosi trading galley.
Laden with cloves, saffron, jet, jade, scarlet samite, and green silk, the Treasure stopped in Pentos after a journey to the Jade Sea. It was infected with the grey death, however, so the Pentoshi killed crew members who tried to disembark and then burned the ship. That did not stop rats on the Treasure, who infiltrated the city and spread the plague. Over two thousand died, including Illyrio Mopatis's wife, Serra.
- ↑ 1.0 1.1 A Dance with Dragons, Chapter 5, Tyrion II.