How to reach Chapterhouse
Chapterhouse is probably the easiest zone to reach from the Rain of Fear expansion pack. Basically all you need to do is head on over to Commonlands and once you're there travel to the middle of the southern wall and you'll find the Fear Crystal which leads to Chapterhouse.
If you need some additional guidance just use my map above; Chapterhouse's zone line is marked with a light blue circle. The picture of the Fear Crystal can be found below.