Familiar faces

— Harry Potter (star Daniel Radcliffe): With his black hair, round glasses and lightning-bolt scar on his forehead, the boy wizard is one of the world's most famous fictional youngsters. Plucked from an unhappy foster home by his magical overseers, he is being trained to use his native powers for good, and to unlock the mystery of his parents' death.

— Hermione Granger (Emma Watson): Harry's curly-haired classmate, Hermione (pronounced Her-MINE-eee) is an eager bookworm saddled with the tag of "know-it-all." She puts her academic image aside in the new movie for courageous field action against old and new enemies.

— Ron Weasley (Rupert Grint): The youngest son in a big family of red-headed wizards, he is best buddies with Harry and Hermione, who is beginning to show hints of more-than-sisterly feelings for Ron.

— Draco Malfoy (Tom Felton): The spoiled rich kid and son of an aristocratic snob, Draco is deeply disliked by Harry and his friends. His relentless goading of Harry and Ron comes back to haunt him in Azkaban.

— Rubeus Hagrid (Robbie Coltrane): The beloved half-giant gamekeeper and "keeper of keys and grounds" at Hogwarts (the academy for training young wizards), he is enlisted to teach Care of Magical Creatures — notably, the beautiful Buckbeak the Hippogriff.

— Minerva McGonagall (Maggie Smith): Deputy headmistress of Hogwarts, she knows secrets that Harry is determined to unlock as a dangerous Azkaban escapee bears down on the school.

— Severus Snape (Alan Rickman): The black-cloaked professor of potions is the scariest teacher at Hogwarts, a fact that Azkaban uses to memorable effect in a vivid classroom lesson on conquering fears.

New faces

— Albus Dumbledore (Michael Gambon): The character is not new but the actor is. Gambon was chosen to succeed the original Dumbledore, Richard Harris, who died shortly after the second film, "The Chamber of Secrets," opened in 2002. In "Azkaban," Dumbledore again plays a critical role in Harry's growth.

— Professor Lupin (David Thewlis): The new teacher of defense against the dark arts bears the signs of a mysterious illness that sometimes keeps him away from the classroom. He becomes an important confidante for Harry, but Snape, for one, does not trust him at all.

— Sybil Trelawney (Emma Thompson): This vaguely hippie-like professor of divination is given to dramatic fits of psychic vision that some professors and students, including Hermione, dismiss as silly theatrics.