I might be screwed then and have to start the DLC over again with the character. About 15 - 20 gameplay hours ago I got the option to speak with Deor to start the quest while Storn Crag-Strider was reading the Black Book (during The Gardener of Men quest). No dialogue options opened up and Deor walked off. Storn was standing there with Mora's tentacles through him from the book and stayed that way. Couldn't get dialogue options with any of the villagers so I just watched the screen, hoping that something would happen between Mora and Storn. I woke up a couple hours later and nothing had changed. Loaded up the prior save and tried again only to get the same result, so I loaded up the prior save again and went about doing other quests.
A couple of hours ago, I found myself in the vicinity of Skaal Village again, so I talked to Storn. No option to speak to Deor appeared, and Storn was stuck again as the book had a hold on him. Without saving, I leave the village to continue the quest I'd been on (Deathbrand) and went back to the village once I'd completed it. Several villagers were now standing shoulder to shoulder with Storn. The book and tentacles were gone. I can see the names of the other villagers around Storn, but his name won't come up and I can't talk to him. Deor and Fanari are still in the same spots they were in before. Looks like I can't advance further in the main quest.