Escape from Durnholde

If you ever lose Thrall on your way towards Tarren Mill, then he is waiting for you on the southeastern side of Tarren Mill on a hill (east of the barn there).

Neat little Easter egg. You can see how Commander Mograine obtained the crystal for Ashbringer. When you get done with the dungeon, look on the map and you should see a road that runs south close to the river. If you follow it, you come to Southshore. Go to the second house on the left which should be an Inn. There, Commander Mograine is sitting at a table conversing with others about a crystal he found. It is fascinating to watch if you're into the Lore.

In the Caverns of Time you can do the Durnholde instance. When you enter the instance, talk to the humanoid Erozion, he will give you these Incendiary Bombs. If for any reason you lose them, go back to him and get more.

Each one of the buildings in the pit at Durnholde has a darker-brown barrel. Place one Incendiary Bomb on each. You will need to kill the guards to do this.

The fires they cause will call Lieutenant Drake.

Then go into the basement of the hold. The basement entrance is under the stairs up.

Free Thrall, and as you leave the gate Captain Skarloc will appear.

You must speak, right click, Thrall to get him to move out of the basement, and again to get him to leave Durnholde for Tarren Mill. Taretha is upstairs in the Inn, which you will reach after Thrall searches the barn, and the church. You must kill the mobs to get Thrall to move on. Click on Thrall to get to the next segment after he finds Taretha.