The party witnesses a massive black dragon appear along a river. It flies up to a mound on an island within the river and utters a shout; Slen Tiid Vo, resurrecting a massive green dragon. The dragons have a dispute and after a few strong words exchanged fly off in two different directions. The black flew further into Eastern Elsweyr, while the green flew north.
The Blackpowder Mercenaries used a sending to relay this information to Svarog. Through conversation and some historical know-how, they were able to identify the black as Alduin and the green as Kaalgrontiid.