What is the plot of the Brave Story?

The movie Brave centers on Merida, a young Scottish princess who values her independence and loves outdoor activities. She is often at odds with her mother, who is trying in vain to turn her into a proper princess and prepare her for marriage. After a particularly intense argument, Merida runs away into the forest where she finds the home of a witch. Hoping to change her mother's mind about forcing her to marry, Merida buys a bewitched tart to feed to her mother. The tart has the unintended consequence of turning her mother into a bear. The two must then work together to change her mother back to a human before it's too late.