Harry is healed and is excused from the Hospital wing. Harry looks for Hermione and Ron and finds them in Moaning Myrtle's bathroom. They already started on the Polyjuice Potion. Harry tells them what happened to Colin, which they already overheard Professor McGonagall telling Professor Flitwick. He also tells them about Dobby. Now they know the Chamber of Secrets has been opened before. They speculate about what kind of monster is in there. Hermione thinks it might be able to make itself invisible or maybe it can disquise itself.. She read about Chameleon Ghouls who can do that. Everybody at Hogwarts is getting afraid and suspicious. Christmas is near and the holiday will be the perfect time to use the Polyjuice potion to get a confession from Malfoy. They still need the Boomslang skin and the Bicorn horn and will try to get it in next Potions class from Professor Snape. On Thursday afternoon, the lesson goes as usual, Draco harrassing Ron by flickering puffer-fish eyes at Ron and Harry. They are making a Swelling Solution. To create a diversion so that Hermione can sneak into Snape's private stores, Harry throws one of Fred's Filibuster fireworks into Goyle's cauldron. It explodes, showering the whole class, Malfoy's nose and Goyle's hands swelling. Professor Snape calls for order and for everyone who has been affected to come to him for a Deflating Draft. Hermione manages to get the ingredients.
A week later, there's an announcement on the notice board that a Dueling Club will be started; first meeting that night. The trio decide to go, wondering who will be teaching. Hermione was told Professor Flitwick was a dueling champion when he was young. Entering, they find out it is Professor Lockhart and that Professor Snape will be his assistant. They start the Wizard's Duel demonstration. On the count of three, Professor Snape uses a Disarming Charm Expelliarmus to blast Lockhart off his feet. Next they will duel in pairs. Neville with Justin Finch-Fletchley, Ron with Seamus Finnigan, Harry with Draco and Hermione with Millicent Bullstrode. They are supposed to start on the count of three. Draco cheats and starts on 2, Harry is hit with a spell but manages to cast a counter Tickling Charm ¤ Rictusempra. Draco casts a spell again, Tarantallegra and Snape stops all duels by casting a ¤ Finite Incantatem. All stop, Lockhart helps up Ernie Macmillan and Miss Fawcett. Next Neville and Justin have to volunteer for a spell blocking demonstration, but Snape has Draco and Harry do it. Snape whispers a curse to Draco and when they start Malfoy casts a ¤ Serpensortia and a black snake comes out of his wand. Lockhart, trying to get rid of the snake, blows the snake ten feet into the air and it falls down again. Enraged, it slithers toward Justin. Harry, sprinting after it, comands it to 'leave him alone!' and miraculously it stops. Everybody is upset and Ron takes Harry away to the Gryffindor common room.
Ron explains to Harry that he is a Parselmouth, someone who can talk to snakes. Speaking the snake language, Parseltongue, is not considered a good quality in general, since Salazar Slytherin was famous for it. The whole school will think Harry is a decendant. Harry is afraid of this, since the Sorting Hat had wanted to put him in the Slytherin house. The next day he wants to explain what really happened to Justin. He goes to seek him in the library. A group of Hufflepuffs are talking and Harry overhears their conversation. He hears Ernie Macmillan trying to convince the others that Harry is the Heir of Slytherin. Harry shows himself and tries to convince them of what he really did at the Dueling Club, with no effect, and goes away.
Leaving, he bumps into Hagrid who tells Harry that his roosters are being killed. He continues and finds Justin and Nearly Headless Nick petrified solid. Peeves appears and starts to shout "ATTACK! ATTACK! ...." Professor McGonagall appears to the spot and takes Harry with her. Justin is taken to the hospital wing by Professor Flitwick and Professor Sinistra of the Astronomy Department. Harry is taken by McGonagall to Dumbledore's office by entering through a stone gargoyle with the password "lemon drop" and up a spiral staircase.
- Daniel Radcliffe - Harry Potter
- Gemma Jones - Poppy Pomfrey
- Chris Rankin - Percy Weasley
- Emma Watson - Hermione Granger
- Rupert Grint - Ron Weasley
- Bonnie Wright - Ginny Weasley
- James Phelps - Fred Weasley
- Oliver Phelps - George Weasley
- Matthew Lewis - Neville Longbottom
- Maggie Smith -Minerva McGonagall
- Alan Rickman - Severus Snape
- Tom Felton - Draco Malfoy
- Joshua Herdman - Gregory Goyle
- Devon Murray - Seamus Finnigan
- Alfred Enoch - Dean Thomas
- Kenneth Branagh - Gilderoy Lockhart
- Edward Randell - Justin Finch-Fletchley
- Louis Doyle - Ernie Macmillan
- Charlotte Skeoch - Hannah Abbott
- Eleanor Columbus - Susan Bones
- Robbie Coltrane - Rubeus Hagrid
- John Cleese - Nearly Headless Nick
- Rik Mayall - Peeves
- Warwick Davis - Filius Flitwick
- Keira Knightley - Aurora Sinistra