"We had followed them into the valley, and found there an obstacle course of sorts, made of Areal thresholds. Apparently they train to leave, make, and enter them as a sport - it's no wonder we were never able to catch them."
— Rastann, guard

"I will take your daughter with me. She shall learn to weave, spin, and dye the mountainsides and shallow seas."The Nightly Travellers are not the friendly helpers they claim they are. They steal children, to raise them in the Area. People staying within the Area for long often become strange and incomprehensible, and nobody knows what this upbringing does to the children.
— Night Traveller Hmakinga
When Nightly Travellers leave the Area, they create astonishing, intricate Areal relics of strange effects, and rulers become worried when they are sighted.
Artists' notes
There are a whole lot of other, friendlier orders with altruistic goals, but describing the freakish, strange orders with intransparent agendas is fun. The others will get their time as well, of course. Meeting a Nightly Traveller is like the opening scene of an urban fantasy novel, when you see a modern mage do something incredible with casual ease.