On Anna's birthday, Elsa and Kristoff are determined to give her the best celebration ever, but Elsa's icy powers may put more than just the party at risk.On Anna's birthday, Elsa and Kristoff are determined to give her the best celebration ever, but Elsa's icy powers may put more than just the party at risk.On Anna's birthday, Elsa and Kristoff are determined to give her the best celebration ever, but Elsa's icy powers may put more than just the party at risk.