Hours 64 & 65: Cairn You Believe It

I decide it's time to get on with some more proper quests to take a break from all the traipsing and grinding. I last did a Dawnguard quest in hour 36, and I've been visiting Isran from time to time for Heavy Armour training, so I think I'll jump back into that.

I have to locate several people - a couple of people Isran knows who can help with the Dawnguard, and a Moth Priest. This involves a bit of travelling through the wilderness. My journey takes me to Dragon Bridge at one point, and I'd forgotten what a nice place it is:

Eventually, I've tracked down everyone I need to, and back at the fortress the Moth Priest reads the Elder Scroll which Serana, the vampire I freed earlier, has handily brought back, having defected from her father Harkon's evil scheme.

I now have to find some more Elder Scrolls, which first entails tracking down Serana's mother. She's in hiding, and we decide that Castle Volkihar itself is probably where she is - 'last place you'd think to look' and all that. We head there and sneak in through a back entrance to the dungeons. There then follows a fairly involved trek through the bowels of the castle, which go on seemingly forever. Eventually, I get stuck and find myself retreading the same ground over and over, getting more and more frantic. After half an hour, I give up and have to consult YouTube - very annoying. I'd missed a hidden candlestick-handle to open a secret passageway.

At the end of the dungeon we discover that Serena's mother has most likely vanished into something called the Soul Cairn. We work out an overly-complicated way of following her (I choose not to become a vampire and instead allow myself to be weakened whilst in the Cairn).

Behold, the Soul Cairn

This is an unrelentingly bleak and forbidding place which is almost completely empty, with just a few scattered bands of skeletal enemies. It's more purpley-blue than just blue like in the picture above. We track down Serana's mother and I complete a fetch-quest type thing to release her from a magical prison. Next, she tells me she has the Elder Scroll I'm seeking and asks me to follow her. However, she doesn't move! I try all sorts of things, including reloading from earlier, and attacking her, but nothing works and it seems I can't proceed with the quest!