Chapter Summaries

Douglas encouraged students across the houses to work harder, then helped Hermione use her Time-Turner more safely by telling her how to reach a hidden room for rest. Hermione, Harry, and Ron opened their club to applicants, where Luna Lovegood baffled everyone with her account of the Crumple-Horned Snorkack, and Draco Malfoy arrived as trouble began.

• Douglas challenged Gryffindor and Slytherin to match each other’s academic performance and offered Hufflepuff a dinner he would cook to encourage them.
• After class, Douglas recognized Hermione’s Time-Turner and advised her to turn it back an extra hour after every two uses so she could rest in the Room of Requirement.
• Douglas gave Hermione directions to the hidden room and used a new spell to imprint the secret in her mind so she could not reveal it aloud.
• Hermione joined Harry and Ron in welcoming students to their club, and Luna arrived seeking help finding a Crumple-Horned Snorkack.
• Luna described the creature to the bewildered students, then left after learning Professor Holmes had suggested the club.
• Draco Malfoy arrived at the classroom, creating a commotion.

Draco Malfoy brought Goyle and Crabbe to join the Charon Detective Agency, whose applicants had to complete a test, and delivered their applications to Douglas. Douglas then questioned Harry about Dementors and deducted three points from Gryffindor for failing to prepare to defend against them.

• Draco challenged Harry over whether Slytherins could join the agency, and Harry gave him and his friends admission tests.
• Draco, Goyle, and Crabbe took the tests after Ron explained that Professor Holmes required them, then left amid jeers from the other students.
• Hermione said the agency wanted Slytherins because they might know more about Voldemort and Black.
• Draco handed Douglas the three applications during Slytherin's Defense Against Dark Magic class, claiming he was saving the Gryffindors the trouble of delivering them.
• Douglas questioned Harry about Dementors in the third-year Gryffindor lesson, urged the students to research them, and deducted three points from Gryffindor.

Douglas expanded the Chamber of Secrets into a founders’ hall and built subject-based assessment areas, while the Defense Against Dark Magic practical classrooms reopened for students. The chapter leaves a fourth-year student confidently beginning the Grindylow challenge as the hidden seventh-year classroom supervisors watch nervously.

• Douglas hung a classroom-monitoring mirror in his office for Sirius, then went to the Chamber of Secrets.
• Douglas greeted Moaning Myrtle and inspected the transformed Chamber, where statues and histories of Hogwarts’ founders had been installed.
• Douglas entered the enchanted archway’s Defense Against Dark Magic assessment area to continue his work.
• With Hogsmeade visits still unannounced, students crowded the practical classrooms on Saturday, including the fifth-year counter-curse room.
• A confident fourth-year student entered the water challenge, using a Bubble-Head Charm and preparing to stun the Grindylows before they attacked.

A fourth-year student’s practical lesson in the Black Lake went wrong when magical plants attacked him, while Douglas tried to bring Sirius up to date and discussed plans to help Muggle-born and poor students. Douglas’s new book was blocked by the Ministry of Magic, and he chose to wait for a better chance to oppose it.

• A fourth-year student was caught by magical plants during a Defense Against Dark Magic exercise and was hauled out by two seventh-years, who explained that Professor Holmes had changed the practical lesson.
• Douglas gave Sirius magazines and Daily Prophet copies to help him catch up with the Wizarding World, and explained his wish to combine Muggle technology with magic.
• Douglas told Sirius that he hoped to establish a foundation for Muggle-born and poor Hogwarts graduates, and asked Sirius to help once his name was cleared and Voldemort was destroyed.
• Douglas explained that his book, Throne of Magic, had been stopped from publication by the Ministry of Magic after a pure-blood family objected to its focus on Muggle technology.
• Mr. Weasley wrote to comfort Douglas and asked to borrow the unpublished book, and Douglas sent him a copy while warning him not to intervene on his behalf.

Sirius considered giving Gryffindor new brooms, while Hermione discovered more of the Room of Requirement’s abilities and helped hold the Charon Detective Agency’s first meeting. Draco Malfoy tried to use the agency to investigate Harry’s connection to Sirius Black, but learned Harry already knew Black was his godfather.

• Sirius asked Douglas whether he should give Gryffindor Nimbus 2001s and Harry a Firebolt, and Douglas advised him to wait until he cleared his name.
• Hermione realized the Room of Requirement could transform into spaces such as a Potions laboratory, bathroom, or reference room, and decided the club should keep meeting in the Defense Against Dark Magic classroom.
• Harry, Ron, and Hermione led the Charon Detective Agency’s first meeting, where Draco was the sole successful applicant from Slytherin.
• Draco offered five Galleons for an investigation into Harry’s relationship with Sirius Black, and Ron accepted the assignment.
• Harry revealed that Sirius was his godfather, leaving Draco shocked that Harry had known and had not challenged Black to a duel.

Draco tried to provoke Harry into pursuing Sirius Black by offering a reward, but Hermione turned the challenge into a Detective Club investigation contract. Draco signed an agreement promising twenty Galleons for evidence about the truth behind Black’s arrest and imprisonment, while secretly hoping Harry and Douglas would die confronting him.

• Draco offered Harry ten Galleons to investigate what he knew about Black and taunted him to seek revenge.
• Harry told Ron and Hermione that he was pretending to be angry and suspected Draco was trying to push him toward Black.
• Hermione negotiated the reward up to twenty Galleons and changed the task to uncovering evidence about the truth behind Black’s arrest and imprisonment.
• George and Fred threatened Draco over his insults about their family, while Hermione stopped them and proposed a written agreement.
• Hermione prepared a parchment contract with a curse and a debt-collection threat involving Dobby, and Draco signed it.

Hermione recruited students to help investigate Black, offering rewards that included magical items from Professor Holmes. Lupin received Douglas's experimental five-flavor Wolfsbane Potion and handed over the Black Lake obstacle course for Douglas to use in practical classes.

• Hermione invited everyone to join the mission to investigate Black, promising Malfoy's Galleons and magical items from Professor Holmes as rewards.
• Sirius asked Douglas whether Malfoy had really sent the students or was trying to frame Harry, and Douglas replied that he could not order a Malfoy around.
• A week before the full moon, Lupin collected Douglas's Wolfsbane Potion and found five varieties: sour, sweet, bitter, spicy, and salty.
• Douglas said the potions could shorten Lupin's time as a wolf and ease the strain of transformation, then suggested that combining the five flavors with seven emotions might suppress transformations.
• Lupin told Douglas that the Black Lake obstacle course was finished and expressed concern about students getting hurt; Douglas said he would use it for outdoor practical lessons for students below third year.

Lupin told Douglas that Harry and the Detective Club were gathering evidence about Sirius rather than accepting the easy explanation that he had betrayed Harry’s parents. After Lupin joined Sirius in Douglas’s office, Snape took over detention and assigned students to copy a hostile book about werewolves, leaving Harry suspicious of his motives.

• Lupin told Douglas that Harry had questioned the evidence against Sirius and that the students had found problems with the original investigation, including the Ministry’s failure to examine Sirius’s wand.
• Lupin discovered Sirius’s secret fireplace passage, agreed to keep it secret, and stayed in Douglas’s office to study with Sirius.
• Douglas announced practical Defense Against Dark Magic training for younger students who passed their theory exams, while the fifth years faced exams in all their subjects.
• Snape replaced Lupin at detention, deducted Gryffindor points from Harry and the Weasley twins, and announced that students would copy Emerett Picardy’s book about werewolves.
• Fred recited the textbook’s account of werewolves as Snape smiled, and Harry suspected that Snape had a reason for choosing the book.

Harry theorized that Sirius Black was a werewolf and discussed the idea with Hermione, Ron, and Ginny, who challenged parts of his reasoning. They remained committed to investigating Black while Hermione privately suspected Lupin and planned to ask Professor Holmes about him.

• Snape tore up Harry’s notes about Black, Snape, and Harry’s parents, punished him for writing during detention, and angrily stopped him from mentioning his father’s rescue of Snape.
• Harry told Hermione, Ron, and Ginny that he suspected Black was a werewolf, linking the theory to Black’s name, his conflict with Snape, and Snape’s lesson on werewolves.
• Hermione and Ginny checked the Daily Prophet and found that Black escaped around June thirteenth, after the full moon, while Hermione questioned Harry’s reasoning.
• Hermione explained werewolf discrimination and Ministry policies, and Harry speculated that Black had escaped to lead werewolves in the Forbidden Forest; Ginny and Ron reminded him that Fenrir Greyback was the Werewolf Leader.
• Hermione privately suspected Lupin was a werewolf and decided to ask Professor Holmes about him, then reminded Harry and Ron that their Defense Against Dark Magic Monthly Exams were the day after tomorrow.

Douglas helped Lupin remain lucid during his full-moon transformation and tested the Homorphus Charm on him, which partially restored his human form. Lupin returned to Hogwarts the next morning looking energetic, easing suspicions among students and allowing the Charon Detective Agency’s investigation to resume.

• Douglas, Lupin, and Sirius went to the Shrieking Shack, where Douglas prepared a meal and Lupin reported that his medicine had kept his emotions under control.
• Lupin transformed into a werewolf while remaining lucid, and Sirius and Douglas reassured him as Douglas examined his condition.
• Douglas cast the Homorphus Charm on Lupin, partially changing him back into human form, and Lupin said he felt wonderful.
• Lupin returned to Hogwarts the next morning in good condition, surprising Hermione and weakening students’ suspicions that he was a werewolf.
• Harry welcomed Lupin’s return because Snape’s substitute teaching and detentions had made his days miserable, and the Charon Detective Agency’s stalled investigation could continue.

Douglas hid Sirius before Snape arrived, then gave Snape the Wolfsbane Potion he had prepared for Lupin and explained how Lupin’s improved condition came from medicinal food. After Snape left for class, Douglas headed to the obstacle course to teach the third-year Hufflepuffs, who feared the practical lesson would punish those who had failed their monthly exam.

• Douglas sent Sirius through the fireplace with Dobby and let Lupin leave before admitting Snape.
• Snape inspected Douglas’s food, took the box of five Wolfsbane potions, and questioned Douglas about Lupin and Sirius.
• Douglas avoided Snape’s probing with Occlumency and reminded him that Potions class was about to begin.
• Snape left with the potion box, and Douglas hurried to the obstacle course for the third-year Hufflepuffs’ practical lesson.
• The Hufflepuffs saw Douglas’s ominous smile and worried that their failed exam results would affect the lesson.

Douglas reprimanded Hufflepuff students who had failed their exam, then introduced Professor Lupin’s obstacle course as training to survive magical duels. He began the first pursuit exercise with Hannah Abbott, who tried and missed a Leg-Locker Curse on an alchemical rat.

• Douglas made the students who failed lean over stone chairs, find the textbook passages for their wrong answers, and reflect on their poor exam results.
• Ernie Macmillan repeatedly talked during the lesson until Douglas called him out, while Justin Finch-Fletchley and Hannah Abbott told him to be quiet.
• Douglas led the students who passed to Professor Lupin’s obstacle course and explained that younger students should use the surroundings to survive or escape dangerous wizards.
• Hannah Abbott asked whether they might face danger from Black, and Douglas gave a mysterious smile before continuing his explanation.
• Douglas set the students the task of catching an alchemical rat through the course and chose Hannah to start; she cast a Leg-Locker Curse but missed as the rat darted ahead.

Hannah tackled Douglas’s obstacle course, facing spell-reflecting traps, dangerous magical plants, and a moving stone statue as she pursued a mouse. She nearly caught it, but a familiar binding spell stopped her, and Douglas sent her out of the course before calling Justin to begin.

• Hannah crossed rubble that reflected her spell, then was ensnared by Devil’s Snare disguised as a Christmas cactus and escaped with fire.
• Douglas explained that Headmistress Sprout had supplied dangerous magical plants, while Hannah cautiously continued after the mouse.
• A stone statue came to life and attacked Hannah, but she slowed it with a Growth Charm before the weeds burst.
• Hannah snapped the branch beneath the mouse with a Reductor Curse and leaped to catch it, but a red spell bound her and sent her crashing to the ground.
• Douglas released Hannah from the course, praised her performance, and called Justin to take his turn.

Justin used Muggle athletic techniques and a Blasting Curse to navigate Douglas’s obstacle course, while Douglas reminded the class to use their magic to clean themselves up. As the Hufflepuffs left and the Slytherins arrived, Draco warned Crabbe that the course was dangerous and was reprimanded by Douglas for talking during the briefing.

• Justin sprinted through the course, used Confringo to expose hidden pits beneath the lawn, and found the mouse climbing inside one of them.
• Douglas told the dirt-covered students to use Scourgify, then restored a student’s hair with a Growth Charm after he accidentally cleaned it away.
• Most students attempted the course before Douglas assigned at least ten inches of homework and asked them to complete the practical through their own efforts.
• After the Hufflepuffs left, Douglas reset the course, and Crabbe smugly imagined winning first place while Draco and Goyle discussed the hazards.
• Douglas rebuked Draco for talking during his briefing and warned him not to let it happen again.

Douglas tested the students on a practical course filled with magical traps, where they had to catch a rat. Draco and Ron both fell victim to the course, while Hermione realized the traps could be more dangerous than she had assumed.

• Douglas chose Draco to go first, and Draco chased the rat into Devil's Snare after putting his wand away.
• Douglas freed Draco from the Devil's Snare and criticized him for leaving his wand in his robes; Draco urged the lesson to continue, and Millicent Bulstrode eventually caught the rat.
• Ron noticed that the rat resembled Scabbers and volunteered to go first, then cast Wingardium Leviosa at it.
• The rat dodged Ron's spell, and a magical trap reflected the spell back at him, lifting him briefly before he fell face-first.
• Hermione asked Douglas whether Ron's spell had been reflected, and Douglas confirmed that the course contained magical traps.

Neville recognized a rare Mimbulus mimbletonia, and Douglas promised it to him if he caught the mouse. Neville began the race by taking the edge of the course, but fell into a concealed pit, leaving Douglas to tell the watching students not to help unless Neville asked.

• Neville identified the Mimbulus mimbletonia among the plants, and Douglas promised to give it to him if he caught the mouse.
• Neville asked to take Ron's turn, and Hermione explained that Neville had a knack for Herbology and would get another chance if he failed.
• Douglas returned the mouse to the start and began the race, and Neville nearly slipped before casting the Serpentine Speed Skating spell.
• Neville moved along the edge of the course to avoid obstacles, but fell into a concealed pit as the mouse watched from the rim.
• Douglas told the students not to rush to help Neville because he had not asked for help.

Neville caught a rat during Douglas’s lesson and won a Mimbulus mimbletonia, which sprayed foul-smelling liquid over the students when someone touched it. After class, Sirius reached Douglas’s office through the fireplace and was kicked aside, but he said he had come to see Harry.

• Neville grew weeds with a Growth Charm to climb out of a pit, froze the rat, and caught it after falling back into the pit with it.
• The students applauded Neville, and other students attempted to catch rats using spells and their own skills during Douglas’s lesson.
• Douglas gave Neville the promised Mimbulus mimbletonia, which sprayed dark green liquid over the gathered students when one of them touched it.
• Douglas realized he had left the fireplace restricted and restored its transportation function, allowing Dobby and Sirius to emerge.
• Sirius charged at Douglas in dog form, but Douglas kicked him aside; Sirius explained that he had come to see Harry.

Sirius and Douglas discussed Scabbers’s prolonged sleep and Douglas’s nightmare spell, while Hogwarts students practiced catching rats and Lupin trained them on the obstacle course. The chapter ended when Lavender Brown broke down after learning her rabbit had died, and Seamus linked the tragedy to a prophecy by Professor Trelawney.

• Sirius waited for Harry to appear in the mirror, and Douglas explained that Scabbers was asleep in a cage enchanted to give him nightmares.
• Hogwarts students took up rat-catching, but Ron could not use Scabbers for practice because the rat would not wake, even when Crookshanks held him in its mouth.
• Professor Lupin led the students through the obstacle course, returned George and Fred’s summoned broomsticks, and warned that the practice rat was no ordinary rat.
• Douglas noticed Lavender Brown losing focus in class, and Parvati told him that Lavender’s rabbit, Binns, had been bitten to death by a fox.
• Lavender said the date was October sixteenth, and Seamus declared that Professor Trelawney’s prediction about a dreaded event coming true had been fulfilled.

Douglas explained that Sybill Trelawney’s casual predictions were usually unreliable, though she sometimes made genuine prophecies about major events, then steered the class back to Defense Against Dark Magic. Later, Professor McGonagall questioned Douglas about Harry’s Hogsmeade permission form and the plan to catch Wormtail, and asked him to let Sirius out of the office occasionally.

• Douglas asked Lavender how Trelawney had made her prediction, then announced that her poor performance had earned her a two-foot assignment.
• Hermione questioned Trelawney’s credibility and her prediction that Harry would die, so Douglas explained the difference between her ordinary guesses and her rare genuine prophecies.
• Douglas reminded the students that they were in Defense Against Dark Magic, and Hermione got the class back to practicing spells.
• Professor McGonagall asked Douglas about signing Harry’s Hogsmeade form, and Douglas said Sirius could sign another copy as Harry’s godfather.
• Professor McGonagall worried that the public rat-catching plan would alert Wormtail, but Douglas reassured her that his potion and the cage he had given Ron were in place.
• Professor McGonagall suggested that Sirius walk around the grounds in his Animagus form, and Douglas said he would take Sirius to watch Gryffindor play.

Douglas attended the stormy Quidditch match between Gryffindor and Hufflepuff with Sirius, while watching for Dementors around the school. The Dementors attacked the pitch, but the students drove them away with Patronus and Dumbing Mist Charms, and the match paused with the Golden Snitch escaped again.

• Douglas brought Sirius to the Quidditch Pitch and watched Hufflepuff narrowly lead Gryffindor as the storm worsened.
• Douglas noticed Dementors approaching and sent more than a dozen wooden plaques toward the sky above the pitch.
• A Dementor attack interrupted Harry and Cedric's chase for the Golden Snitch, and a white crane Patronus appeared from Harry's chest to protect him.
• Students used Patronuses and Dumbing Mist Charms to drive the Dementors away, while a silvery-white cat chased off others near the stands.
• Harry stopped Cedric from pursuing several gray shapes belonging to Professor Holmes, and Madam Hooch's whistle called them back down to the pitch.