Pan's Labyrinth
This is an interesting movie. I believe it is of the magical realism genre: the director (Guillermo del Toro) has, in my opinion, left wiggle room for two views.
In this film, Ivana Baquero plays Ofelia, the daughter of Carmen (played by Ariadna Gil). Carmen is recently widowed and has been wed by the influential Captain Vidal (Sergi Lopez) at the depth of the Spanish Civil War. Carmen is pregnant with Vidal's son (he knows it's his male heir and will brook no dispute).
Vidal is a heartless murderer, stamping out the revolutionaries to keep Spain safe for Franco and the Catholic church, and much of what del Toro puts in the film is a denunciation of both. Del Toro is excellent in his drawing of Vidal's character - we see Vidal in his dressing room and on the battlefield, compelled to heroics by his father's heroic death in battle. Vidal is a monster: sadistic and heartless. He is reality in the Spanish civil war.
Ofelia spends time reading fairy tales and believing them to be true. Her mother chides her gently; Vidal takes her to task more strenuously. Del Toro shows us Ofelia's fantasy land, and we are left with enough vagueness that some can say her fantasies are real and some can say her fantasies are her escape from the hell of the war. And given the monster in her life, who can fault her for her escapism?
If the fantasy is correct, Ofelia is the daughter of the king and queen of the underworld, and she strayed above ground for too long and lost her memory. She needs only to find her way back to assume her rightful position as heir to the crown. She finds a faun in an old maze who proposes to test her to see if she really is the princess, and she accepts the challenge. In the fantasies she faces monsters and monstrosities, sometimes failing, sometimes succeeding. If her fantasy is reality, she passes the ultimate test and goes to her mother the queen and her father the king of the underworld, takes the throne and lives happily ever after, beloved by all her subjects.
We are, however, given an alternate universe. A heartbreaking world where the monster is her mother's husband, where life has no value, and where no one can pass the ultimate test. If this story is reality, she fails and does not live happily ever after.
You choose which version to believe is true, and then you can think about what your choice says about you. Pay attention to all the details, fairy tales, rules, and books. There is a rich story in this movie, and your attention is well-rewarded.