On the night before the trip to the winter holiday, a boy dreams of the adventures he will experience in the mountains. Of course, he wants to try his new skis on a steep descent. He disdains the hill for beginners on which his sister practices. During his daring ride from the highest mountain, the boy gets into the rails of the railway and bumps into the end of the train. But since this happens in his dream, he manages, with the help of his sister, to pull the compressed train apart again like a harmonica. Both children get on the train and go home.