I'm doing the Dawnguard quest line for the third time now and every single time I'm having the same problem. I get lost in the Forgotten Vale!
After 2 hours of agony I finally reached the Inner Sanctum, only to find out that I only have 4 of the 5 vessels. Apparently I've missed one Way Shrine. What is the best thing to do here? Load an old save and start the Forgotten Vale from the start? Or go back trough the portals and look for that one forgotten way shrine? This part of the quest is always driving me completely insane.