When Jack Frost pays a long overdue visit to his friends Hiccup and Merida, Hiccup receives an unexpected invitation from a foreign kingdom called Arendelle, in regard to princess Elsa's coronation. Claiming he was arranged to be married to Elsa. A shocked and confused Hiccup learns the ancient story behind this arrangement that had been put off since the first kings of Berk ever laid eyes on a dragon. And soon takes off for Arendelle. However, the journey to meet the mysterious soon-to-be Queen and settle this misunderstanding turns far more chilling than anticipated.