Disa in the Land of the Northern Lights

Disa feels her heart skip a beat, and her feelings tie themselves into a lump in her throat.
This is the last time she will see her friends.
She is going away to Iceland, where she does not know anyone.
In the land of the northern lights, Disa is lucky enough to make friends with the boy Kamban.
Disa has to find the magic brimstone-buttercup.
She can only succeed if she has the ability to see the invisibles.
Disa in the Land of the Northern Lights
Disa and the Hidden People
Disa's Battle