Everything Clara (Mackenzie Foy) wants is a key – a unique key that can open a box containing an invaluable gift from her mother who died a long time ago. A golden thread she finds at the Christmas party organized by her godfather Drosselmeyer (Morgan Freeman) leads Clara to the hidden key, but it disappears strangely and mysteriously in a stunning parallel world.
In that world, Clara meets a Phillip (Jayden Fowora-Knight) soldier, a group of mice and regents who run the three kingdoms: The Land of the New Flags, The Land of Flowers, and The Sweet Land. Clara and Phillip have to venture into the dangerous Fourth Land, the house of tyrant Mother Ginger (Helen Mirren) to recover the key that Clara wants and hoping to bring harmony back into the unstable world.