You move in on the Tower of Mist looking for the dragon that Beandr is pursuing.
Outside the tower is a camp of dragonborn raiders and a group of reptilian hybrids who seem to be working for them. These hybrids are similar to the ones that you saw fishing earlier and whom you fought along with the giant eel-like reptile.
You surprise the dragonborn and their guards and take them out. Then a strange dragon emerges from a large pond near the tower. The dragon looks like a black dragon, but upon closer inspection you notice that it also has features of a bronze dragon and a definite bronze tinge to its black scales.
The dragon does not have the typical powers of a black, but rather has a mix of black and bronze dragon powers, including healing while under the water.
After you defeat the dragon, you explore the camp and find a stash of gold and platinum. On the body of the dragon you find an Eladrin Ring of Grace.
You investigate the tower that the dragon was guarding, and discover the body of Tobolor, turned to stone, Hallabiri’s backpack, and the book of the lore of the Dragon Queen, the book that Nimozaran originally sent you to find.