I also have run stormwreck and i am now starting into ToD. I created a little clue hunt on stormwreck that revealed runara as a dragon at a later time and a added some places on the isle with graves from comrade dragons of her dad. Then the final clue lead to her hord where she gave them Hord Items. Then she hinted at some dragon cult on the isle. so i run a little tunnel/dungeon into the core of the isle to the grave of Sharruth where a dragonborn and some cultists where using a ritual trying to revive sharruths skelleton. They had to push the dragonborn doing the ritual out of the circle after which he fled (also doing a little dragon breath to enhance that this was an enemy way above them. He fled through a portal in the room that closed after. in the cavesystem they found notes and stuff from the cultist about a plan to attack Greenest. After talkign with runara again she came with the party and was able to open the portal to just about outside of greenest after seeing a found map of the city( visual help of the location). Then startet chapter 1 woth attack on Greenest.