Mr. Winter. Pratchett T.

in late autumn, dark Morris dance in the night forest: a dance that welcome the onset of winter. But once among the dancers, the young witch Tiffany was taken among the dancers - and the winter, a powerful ancient spirit attracted attention. He is the one who shackles the rivers in the ice, bring down snowfalls to the ground and brings a fierce cold with him. Now he fell in love with a girl who dared to dance with him, and for the sake of her he decided to become a man. And he is ready to present Tiffany Royal Gift: Eternal Winter...

The third book about the adventures of the young witch Tiffany.