When Rosie finds a Russian doll high on a shelf in the big dining-room of her great-aunt Rosamund's Scottish castle, she opens up the two halves of the doll, and finds another one underneath, and another one, and another one, until she's left with a tiny Russian Princess doll in the palm of her hand. Rosie says hello straight away, just like Great-aunt Rosamund told her to, and she's whisked away in a flurry of sparkling snowflakes, on another adventure! This time Rosie finds herself in Russia, and meets Princess Anastasia. The evil witch, Baba Yaga, has cast a spell on Anastasia's family, so her parents, the tsar and tsarina, and all the royal court have been turned to ice. Baba Yaga hasn't turned Princess Anastasia to ice because she collects the tears of young girls to use in magic spells to make her look young and beautiful. Will Rosie and Anastasia be able to come up with a plan to save the royal household, and banish Baba Yaga back to her tree house in the Great Forest?