Against All Odds
After you complete An Ancient Curse (Part Five), destroy the Wild Hunt on the Bald Hilltop and do the Kingdom project, a new segment of the task will start. Rule the kingdom until it’s 60-70 days before the preparation to the sixth part of An Ancient Curse. Linzi and the Storyteller will arrive at the castle and tell you that Nyrissa is going to attack the kingdom for the last time. Meanwhile, the portal to the First World has opened in the Thousand Voices.
Head for the Thousand Voices which is northwest of Pitax (the map is covered with trees). Find a dimension door for the Castle of Knives in the top left corner. When you get there, go up and right to find the Knurly Witch and the Wriggling Man. Deal with them, then talk with Shyka (you saw her in Nyrissa’s dream), and the First Crown quest will start.
Stay at this location and walk upwards, keeping the right edge. Go left and then right as far as possible and you’ll get to the portal to the First World.