The Garcia-Shapiro family visit the Kinney family in England for Christmas, and their daughters, Isabella and Emily become fast friends. A nutty toymaker named Clyde joins the party and gives them two nutcrackers. While the girls sleep Mouse King Doofenshmirtz and his army of mice attacks them, and the nutcrackers become two young boys named Phineas and Ferb, and defend the girls. Doofensmirtz, uses a spell to shrink Isabella and Emily, and kidnap them demanding the princes' surrender in exchange for their lives. The two Nutcrackers/Boys along with two wacky toys, a wind-up monkey named Baljeet, and a jack-in-the-box named Buford, then vow to go on a journey to save the girls before it is to late.