It is mid-winter's night in northern Sweden, a magical night when the sun never sets. On this night, lonesome Dunderklumpen sneaks sneaks into the house of the Wolger family where the little girl Camilla is already asleep. He brings to life some of her toys--Lionel, Doll, Pellegillot and Dummy--and then steals them away to be his new friends. Hearing the toys' cries for help, Camilla's brother Jens goes after Dunderklumpen across the lake and his father trails along trying to catch up with his son.