Wednesday afternoon, 29 May, 1963. Three boys are playing soldiers in the vast dunes of the Flemish coast. When one of them finds his sister making love deep in the dunes, their brother-sister relationship is put severely to the test.

Cityboy Niilas (12) is sent to his mother in Lapland. The only one succeeding in making contact with him is his new sister Suna (11). She takes him on a journey in the magical woods where shy Niilas turns into a wild cloudboy.