LOS ANGELES

When last we left our magical hero, Harry Potter had survived a perilous freshman year at Hogwarts School of Witchcraft and Wizardry and defeated his reincarnated nemesis, the wicked Voldemort.

After all that, the 12-year-old's second school year should be as simple as a card trick, right?

Maybe ... except for the menacing voice Harry hears in his head, the bloody threats that appear on his walls and the strange force that keeps locking his friends in a petrified state of terror.

"Harry Potter and the Chamber of Secrets," the second installment of author J.K. Rowling's novels and the basis for the movie opening today, continues the story started in "Harry Potter and the Sorcerer's Stone," but is generally considered darker and more sinister than the first.

To help Muggles (nonmagical folk) keep track of Potter's world, here's a Hogwarts yearbook of sorts -- documenting the heroes, villains and creatures from both stories, including performers' names with a brief synopsis of their characters.STUDENTS

Harry Potter

Who: Second-year student at Hogwarts.

Bio: The mop-haired, bespectacled boy is a legend in the wizard world, revered as "The Boy Who Lived" for surviving a murderous attack by the tyrannical warlock Voldemort, who left a lightning-shaped scar on his forehead. Voldemort orphaned Harry by slaying both of his parents, and Harry had no idea he was magical until his first year at Hogwarts, having lived most of his life in the stiflingly unhappy home of his Muggle foster parents, the Dursleys. At Hogwarts, the outcast boy finally found a place he belonged and excelled at the broom-flying sport of Quidditch.

Performer: Daniel Radcliffe.

Ron Weasely

Who: Second-year Hogwarts student, best friend of Harry.

Bio: An unlucky, middle-child of the red-haired Weasely family, Ron helped Harry recover the Sorcerer's Stone in the first story by nearly sacrificing himself during a game of life-sized enchanted chess, one of the traps guarding the magical element from Voldemort. He lacks Harry's strength and Quidditch skills, and isn't as studious as Hermione Granger, but Ron remains a loyal sidekick who is eager to escape the shadow of his many older siblings.

Performer: Rupert Grint.

Hermione Granger

Who: Second-year Hogwarts student, friend of Harry and Ron.

Bio: A brainy, bookworm and cohort of Ron and Harry's in the Hogwarts dormitory of Gryffindor Tower, she has a penchant for helping unravel school mysteries by quoting from the book "Hogwarts: A History." Her parents are Muggle dentists, and some of her more sinister classmates disparage her as a "mudblood" for not descending from "pure" wizard ancestors.

Performer: Emma Watson.

Draco Malfoy

Who: Second-year Hogwarts student.

Bio: This sneering, slick-haired resident of Hogwart's sinister Slytherin house delights in causing grief for Harry and his friends. He mocks Hermione as a "mudblood" and teases Ron for coming from a poor family. Draco is bold and cruel, and is not opposed to using his family's wealth and power to get ahead.

Performer: Tom Felton.

Neville Longbottom

Who: Second-year Hogwarts student.

Bio: This absent-minded and clumsy Gryffindor chum comes from wizard parents but isn't very talented at magic. Hermione stunned him with a petrification spell when he tried to stop them from pursuing the Sorcerer's Stone, but the school headmaster, Albus Dumbledore, praised the hapless Neville for standing up to his friends.

Performer: Matthew Lewis.

Vincent Crabbe and Gregory Goyle

Who: Hogwarts students, Draco Malfoy's goons.

Bios: This thick-browed, slow-thinking pair shadow their friend Draco and help carry out his mean-spirited pranks. They've got muscle, gluttonous appetites and a love for bullying anyone who doesn't belong to Slytherin house.

Performers: Jamie Waylett and Josh Herdman.

SPIRITS AND CREATURES

Voldemort

Who: A powerful Dark wizard who waged war in the magical world.

Bio: Often referred to in hushed, fearful tones as "He Who Must Not Be Named," Voldemort was vanquished when his lethal curse on Harry backfired. During Harry's first year at Hogwarts, Voldemort reappeared in search of the life-restoring Sorcerer's Stone -- surviving only as a parasite on the body of Hogwarts teacher Quietus Quirrell. Although Quirrell was destroyed, Voldemort's spirit escaped.

Performer: voice of Richard Bremmer.

Nearly Headless Nick

Who: The resident ghost of Gryffindor Tower.

Bio: This floating, ectoplasmic gentleman prefers his full name, Sir Nicholas de Mimsy-Porpington, to his nickname -- which refers to the botched beheading that left his noggin still partly attached to his body.

Performer: John Cleese.

Moaning Myrtle

Who: Ghost of a Hogwarts student.

Bio: Lonely and mistreated in life, Myrtle has moped in a Hogwarts women's lavatory ever since her early end. She prefers to hide in the S-bend of one of the toilets, which usually leads to plumbing problems. Harry, Ron and Hermione like to make their plans in her bathroom, since nobody goes in there due to the whining of her nerdy, needy ghost.

Performer: Shirley Henderson.

Dobby

Who: House elf.

Bio: He's Harry's annoying savior. Dobby knows about a secret plot that could harm Harry during his second year at Hogwarts, so he uses magical mischief to dissuade the boy from returning. The house elf, who can't say which wizard family he serves, wears a soiled pillow sack. His owners can't give him new clothes because that would break the spell that binds his loyalty.

Performer: voice of Toby Jones.

FAMILY

James and Lily Potter

Who: Harry Potter's deceased parents.

Bios: Harry's mother was born to Muggles, but she had mystical powers anyway which brought her to Hogwarts where she met her future husband. Both were slain by Voldemort, but Lily's decision to sacrifice her own life to protect Harry led to a magical protection for the boy.

Performers: Adrian Rawlins and Geraldine Somerville.

Vernon and Petunia Dursely

Who: Harry's foster parents.

Bio: Aunt Petunia is the nonmagical sister of Harry's mother, and she grudgingly took in Harry when his parents were killed. She and her husband dislike Harry and made his bedroom the tiny cupboard under their stairs. Their perpetual mistreatment of Harry is contrasted by their blind devotion to their grouchy, greedy son, Dudley.

Performers: Richard Griffiths and Fiona Shaw.

Arthur and Molly Weasely

Who: Parents of Ron Weasely.

Bio: Arthur has earned only a modest living as a civil servant at the Ministry of Magic, so his family of six boys and one girl has made do with a lot of hand-me-downs. Molly Weasely knits garish sweaters for all her children each Christmas and treats the orphaned Harry as one of her own. Ron's older brothers include Bill, a magical banker in Africa; Charlie, a dragon researcher in Romania; Percy, an uptight prefect at Hogwarts; and Fred and George, twins who hope to someday own a joke store. His little sister, Ginny, is a first-year student nursing a crush on Harry.

Performers: Mark Williams and Julie Walters.

Lucius Malfoy

Who: Draco Malfoy's father.

Bio: This wealthy wizarding patriarch was a former supporter of Voldemort who now claims he was deluded into serving evil. He maintains sinister intentions and displays the same icy disregard for manners as his wicked son. To help Draco secure a place on the Slytherin Quidditch team, Lucius purchased state-of-the-art brooms for the entire squad.

Performer: Jason Isaacs.