Plot: In the Victorian England, the teenager Clara is a young scientist that lives with her older sister Louise, her younger brother Fritz and her widower father Mr. Stahlbaum. The family misses their mother and wife Marie Stahlbaum, who was also a scientist and has recently passed away. On the Christmas Eve, Mr. Stahlbaum delivers a gift left by Marie for each sibling and Clara receives an egg-shaped locked box without a key to open it.