Chapter Summaries

Douglas showed Slane his new novel, whose protagonist’s magical innovations reflected Douglas’s own ideas about reforming magical education and industry. Slane planned a major promotional campaign, while Douglas explained that he wanted children to learn magical technology.

• Slane read Douglas’s novel and questioned its depictions of Snape, the protagonist’s magical techniques, and rune-powered gloves.
• Douglas explained that the protagonist’s methods drew on his own research and that Hogwarts students already practiced the Frequency Adaptation Method.
• Slane recognized that the novel incorporated Douglas’s plans for magical education, rune standardization, and assembly-line production, then proposed promoting it through the Daily Prophet and other publications.
• Douglas said he would resume updates to his old book after completing the first volume of the new one, and Slane agreed to arrange a teaser campaign.
• Before leaving, Slane asked Douglas what he hoped to achieve with the novel, and Douglas said he wanted children to know that magical technology education should start young.

Sirius opposed Percy’s new magical energy laws, but the Wizengamot passed them and counterfeit Charms Rifles soon appeared in Knockturn Alley. After Sirius publicly defended the Marauders Power Company, Percy urged Cornelius Fudge to use the incident to investigate pure-blood families with histories of dark magic.

• Sirius mocked Percy’s proposed Magical Energy Product Access Act and Magical Energy Weapons Control Act, while Percy insisted the laws were necessary for public safety.
• Percy and Sirius argued over whether the new restrictions targeted Sirius’s company, then Percy bumped into Sirius and declared that he trusted the boss.
• The Wizengamot passed both acts, and three days later counterfeit Charms Rifles caused a violent clash in Knockturn Alley that made the Daily Prophet’s front page.
• Sirius dismantled a confiscated rifle at a press conference and claimed someone had forged dark magic weapons to frame the Marauders Power Company.
• Cornelius Fudge raged over the accusations, and Percy urged him to investigate pure-blood families suspected of funding or sheltering Dark Wizards.

Fudge signed a search warrant against the Marauders Power Company as the Ministry’s conflict with the company escalated, while Lucius sought Voldemort’s advice about the magical energy rifles. Voldemort replied “Do nothing,” and Lucius went to find Snape, where Peter Pettigrew was suffering through a potion test.

• Scrimgeour pressured Fudge to sign the search warrant, while Percy warned that the Wizengamot had encouraged a clash between the Ministry and the Marauders Power Company.
• The Quibbler published Xenophilius Lovegood’s claim that Black and Fudge were conspiring to seize power and replace wands with fake guns.
• Lucius learned that Fudge had signed the warrant and sent Voldemort a letter asking how to handle the magical energy rifles.
• Voldemort dismissed Lucius’s letter, struggled with teaching and research duties, and sent back the reply “Do nothing.”
• Lucius burned Voldemort’s reply and visited Snape, who was testing a Soul Affinity Improvement Potion on Peter Pettigrew.

Snape and Lucius discussed the Ministry’s impending searches and the Dark Lord’s response to rogue weapons, while Peter Pettigrew suffered under their watch. In London, Douglas read Dobby’s unexpectedly sweeping plan to found an elf nation and challenged him about its ambition.

• Lucius told Snape that Fudge had signed a search warrant and that Aurors would soon search pure-blood families with Dark Magic histories.
• Snape and Lucius blamed rogue Death Eaters for provoking the Ministry, while Snape silenced and then released Peter Pettigrew as he endured torment.
• Douglas reviewed Dobby’s document, titled “General Strategy for Founding the Elf Nation,” and found it far beyond a cookbook.
• Dobby explained that his project had grown from collecting Hogwarts kitchen recipes into a detailed nation-building plan, and Douglas teased him about the scale of his ambition.

Dobby presented Douglas with a plan to help house-elves gain independence, and Douglas approved it. Meanwhile, Sirius faced a Ministry inspection of his company over alleged illegal weapons as Halloween approached.

• Dobby explained his strategy for house-elves, including building unity and establishing domestic service as their path to survival, and Douglas approved the plan and offered support.
• Dobby left in tears of gratitude, while Wangcai accepted a Galleon from him despite Douglas warning that Wangcai never returned money.
• Douglas reflected on the paths Hermione, Lupin, Black, and Neville were pursuing and wondered what Harry Potter was doing, then examined his system and its mysterious cultivation books.
• Scrimgeour arrived with Aurors, including Tonks, to search Sirius's company under a warrant signed by Minister Fudge over alleged unregistered soul-related weapons.
• Sirius challenged Scrimgeour about the new law and warned that the Ministry would owe full compensation if the search damaged his production lines.

Sirius led Scrimgeour and the Aurors through the Marauders Power Company's Any Doors to inspect its factory, where Scrimgeour negotiated a deal for household dust cleaners instead of gaining access to weapons. After spotting the Weasley Twins, Scrimgeour privately offered to help Sirius against Holmes and Fudge, while Sirius recognized that Scrimgeour was maneuvering for his own purposes and invited him into the room.

• Sirius took Scrimgeour and the Aurors through an Any Door to the Marauders Power Company's factory, where Scrimgeour complained that the Aurors could not use the teleportation system.
• Scrimgeour demanded to see weapons, but Sirius offered him a deal on household dust cleaners, and they agreed that the Auror Office would receive half of the machines.
• Tonks knocked into a stack of finished products, and Sirius later praised her while promising to give Moony a month's leave when he returned from Australia.
• Scrimgeour spotted the Weasley Twins entering a room and followed them, then told Sirius he had joined the operation partly to help him against Holmes and Fudge.
• Sirius understood that Scrimgeour considered him easier to control than Douglas and invited him into the room, warning that it might not be what Scrimgeour imagined.

Scrimgeour led the Aurors to search Newt’s Acromantula research laboratory over accusations that it was developing illegal soul-targeting weapons. Newt explained the dangerous research and its strict safety measures, leaving Scrimgeour to decide whether to proceed with the search under those conditions.

• Fred and George argued over how to reinforce magical armor without making it too heavy.
• Fred and George mocked Scrimgeour and Sirius as Scrimgeour announced the Aurors’ intention to search the laboratory.
• Sirius told Scrimgeour that he funded Holmes’s work but knew little about the experiments, and promised to support shutting the lab if the Aurors found prohibited weapons.
• Newt emerged from the laboratory, and Scrimgeour asked him to explain the soul toxins listed on the sign.
• Newt said the team studied dying Acromantula secretions and developed an antidote, then warned that anyone entering the lab would need protective robes and must avoid marked objects and the creatures in its deepest section.
• Sirius confirmed that he had never entered the lab and said Douglas had registered the experiments with the Ministry.

Fred and George pitched their lightweight protective fabric to Scrimgeour during the Ministry’s inspection, presenting it as a practical by-product of research. Scrimgeour showed immediate interest in buying Auror uniforms, but Sirius took over the negotiations and offered a slightly larger discount.

• Fred criticized traditional protective robes, and George introduced the twins’ lightweight fabric made from Acromantula silk, mithril microfilaments, and a detoxified spiritual coating.
• Scrimgeour tested the fabric and was impressed by its resilience and potential to reduce the effects of curses.
• Fred and George framed the fabric as a commercial use for research by-products, while Sirius praised their sense of duty.
• Scrimgeour asked about Ministry registration, and Sirius said the sample batch was due for approval but could be reported to Scrimgeour during the inspection.
• Fred and George offered the Ministry a two-percent discount in exchange for Auror combat-test data, but Sirius interrupted and offered a two-point-two-percent discount on finished uniforms.

Scrimgeour withdrew the Aurors after agreeing to discuss the research project with Sirius, while Douglas’s students continued their training and dungeon exploration. On the fifth level, Harry revealed a lion emblem in a sealed stone door, and Ron tried to open it by declaring his Gryffindor pride.

• Scrimgeour ordered the Aurors to withdraw and said his office supervisor would discuss the Magizoology project with Newt the following Monday.
• Sirius refused to fund Fred and George’s research and told them Douglas would have to ask him at the Griffin's Nest.
• Gryffindor and Slytherin students maintained friendly appearances in class while secretly attacking one another with spells.
• The Charon Detective Agency cleared the first four dungeon levels and reached a smooth stone door on the fifth.
• Harry’s Probe Charm revealed a glowing red-and-gold Gryffindor lion beneath the door’s surface.
• Ron shouted that he was a Gryffindor and praised Godric Gryffindor, hoping to win the door’s approval.

The students discovered that the stone door accepted ink carried by a physical medium, not spells, and a Ravenclaw boy began drawing the lion challenge on it. As his lifelike image took shape, Ron wondered whether the door concealed a chamber left by Godric Gryffindor.

• Ron, Seamus, Harry, and others tried shouting passwords and using magic to reproduce the lion, but the stone door did not respond.
• A third-year Ravenclaw suggested drawing on the door with an ink-dipped quill, and the ink remained on the stone and glowed.
• Hermione said she could not draw the realistic lion, and Ron said he and Ginny lacked the skill.
• The Ravenclaw boy volunteered to draw the lion, explaining that he had studied sketching and remembered its proportions and shading.
• The boy drew a lifelike lion on the door while the students watched, and Ron speculated that a secret chamber lay behind it.

The Detective Club grew convinced that a magically sealed door on Hogwarts’ fifth underground level might conceal Gryffindor’s treasure and the Sword of Gryffindor. Hermione and Neville reported their discovery to Professor McGonagall during the Halloween Feast, leaving the Club’s permission to continue exploring unresolved.

• A Ravenclaw student doubted that the fifth underground level held a Founder’s treasure, but a Hufflepuff student, Ron, and others argued that the door might conceal Gryffindor’s legacy and the missing sword.
• Hermione’s pocket watch warned that the Halloween Feast was starting, and Harry sent prefects Hermione and Neville upstairs while the other students stayed to investigate the door.
• Harry told the Club that they were working under an official commission and should not withdraw unless Professor McGonagall confirmed a danger.
• At the Great Hall, Neville told Professor McGonagall that the Club had found a lion-marked door and suspected the Sword of Gryffindor was behind it.
• Douglas noticed Neville’s report, and Hermione explained that the Club was only deciphering the door’s magic and needed help drawing the lion.

Dumbledore allowed the students to keep investigating the mysterious dungeon door until midnight, while Hermione and Ginny discussed cases related to the Intelligent Creatures Act. Dumbledore then revealed that he had found the door years earlier while seeking a hiding place for the Philosopher's Stone and had chosen to leave it intact.

• Dumbledore praised the students’ curiosity, granted them permission to investigate until midnight, and sent Hermione and Neville back to their duties.
• Hermione questioned Neville’s tactic of speaking up to prevent Professor McGonagall from stopping them, then joined Ginny to discuss their cases.
• Pansy wondered whether Harry and the others had found something in the dungeons, while Draco dismissed the possibility that they had found the Sword of Gryffindor.
• Draco defended his mother’s cooking and mocked the Nott family, prompting Theodore Nott to fall silent.
• Pansy urged Draco, Goyle, and Crabbe to investigate the dungeon door, and Draco said Potter might welcome a founding member’s support.
• Dumbledore told Professor McGonagall that he had discovered the door five or six years earlier while searching for a hiding place for the Philosopher’s Stone, and had left it because he found its design ingenious.

At Hogwarts, Douglas explained that the dungeon challenges were made from lessons he and his friends had studied, while the Detective Club finished painting a lion on a stone door. The lion came alive and leaped out of the wall, leaving the students facing a three-dimensional creature.

• Douglas told the professors that the dungeon held no dangerous challenges and explained who designed the sections for Ravenclaw and Slytherin.
• Hermione and Neville brought food to the students working underground, and Neville said Dumbledore had allowed Detective Club members to stay out until midnight.
• Eddie Carter finished painting the lion, and Hermione noticed that the stone seemed to be absorbing the ink.
• Harry pulled Eddie back and ordered everyone to retreat as the painted lion emerged from the stone door and leaped into the room.

A magical lion’s Thunder Lion Roar overwhelmed the students until Hermione silenced the sound, and Neville organized a defensive retreat. The lion then praised someone as a worthy Gryffindor, and Harry suspected it was not one of Godric Gryffindor’s relics before it blinked at him.

• The lion unleashed a deafening roar that hurt the students and threatened their Protective Charms.
• Hermione cast See No Evil, Hear No Evil, stopping the roar and temporarily leaving everyone unable to hear.
• Neville formed a defensive line and ordered the younger students to retreat while Ginny argued with Ron about staying to fight.
• The lion declared that someone who had endured its Thunder Lion Roar was a worthy Gryffindor, prompting confusion among the students.
• Hermione suspected the lion followed a simple trigger condition, and Harry wondered whether it was truly one of Godric Gryffindor’s relics.
• The lion blinked playfully at Harry after Neville praised the Fat Lady.

The Swiftwind Sword Club encountered Professor Holmes’s singing lion trial, and Ginny earned a magical paper-cut lion by facing it bravely. After Ron was burned trying to open the door, Hermione disarmed its traps and revealed another Counter-curse classroom, leaving Harry and Ron to persuade the others to explore it.

• The lion sang Professor Holmes’s rewritten song and challenged the group to show courage before approaching.
• Ginny faced the lion, which vanished into a paper cutting that could animate into an attacking and message-carrying lion.
• Ron guessed the trial might have been made by Bill and burned his hands when he tried to push open the heated stone door.
• Hermione broke the spells on the door, revealing an empty room with a stone coffin that seemed to be another Counter-curse classroom.
• Hermione and Ginny left to organize their case studies, while Harry and Ron encouraged the club members to challenge the classroom for a chance at the Horus Cup tournament.

Douglas discussed the discovery of the old Hogwarts dungeon treasure with Bill during a Halloween video call, while Dumbledore visited Douglas to work on a Ministry report. The call ended with Bill embarrassed about his school prank and Wangcai stealing a Galleon.

• Douglas told Bill that Harry's Charon Detective Agency had discovered the Gryffindor Treasure in the Hogwarts dungeons.
• Dumbledore joined the call and revealed that he had allowed the children in the Karen Detective Club to explore the dungeons until midnight.
• Douglas explained that his suggestion for Ministry asset reports had led Fudge to request one from Dumbledore.
• Pheobe asked what Bill had hidden in the treasure, and Douglas revealed that Bill had left a replica Gryffindor sword worth two hundred pounds.
• Wangcai snatched Douglas's Galleon and retreated into the Fortune Basin.

The Charon Detective Agency explored the sixth dungeon level and found a strange Ravenclaw-like chamber whose entrance tested their memory. After the sequence changed and grew more complicated, the frustrated group was interrupted by Luna, who had just arrived after getting lost.

• Harry assigned the younger students to the fifth-level counter-curse chamber and led the older students farther underground.
• The explorers found a stone door marked with an eagle and thirty stone balls that lit up in sequence.
• Cho Chang tried pressing the balls in the order she remembered, but a countdown began and the chamber reset.
• The second sequence changed and became more complicated, leaving the group unable to memorize it.
• Ron suggested fetching Hermione, but Luna arrived and asked what was wrong.

Luna joined the Karen Detective Club members at a stone door whose flashing pattern had become too fast for them to decipher. She suggested they had misunderstood Professor Holmes’s way of thinking, leaving Neville to wonder whether the door’s rules were meant to be broken.

• The students failed to divide the stone door’s rapid flashes into sections they could memorize.
• Luna asked why no one had tried thinking about the door the way Professor Holmes would.
• Ron accused Douglas of designing the door to torment them and claimed he had heard of a research report about breaking underage wizards’ psychological defenses.
• Harry publicly distanced himself from Ron’s remarks, then asked Luna what she had in mind.
• Luna said the students were trying too hard to be good students and reminded them that the professor enjoyed breaking rules; Neville wondered whether the door’s rules were meant to be broken.

Luna ignored the flashing sequence and opened the stone door by pressing its thirty spheres in order. The door revealed a darkness that no Lumos spell could pierce, leaving the group cheering Luna while wondering what lay beyond.

• The stone spheres flashed in a chaotic pattern, ruining the group's relay memorization plan.
• Luna said the lights were only for looking at and walked to the door without memorizing their sequence.
• Luna pressed the spheres from left to right, and the countdown did not restart.
• Luna pressed the thirtieth sphere, opening the door onto impenetrable darkness.
• Harry began applauding, and the group cheered Luna for solving the mechanism.
• Luna said the Wrackspurts had told her that a straight line was often the hardest shortcut to spot in a maze.

Douglas demonstrated Blind Man's Reckless Horse to Sirius, revealing how it could reverse a target's perceptions and steer them into danger. Sirius learned that Douglas had devised two related spells during his student days, and Douglas left Sirius's question about the centaurs unanswered.

• Sirius asked Douglas whether the trials beneath the Castle were safe, and Douglas explained that his contribution to the final trial required students to master the earlier ones.
• Douglas cast Temerabyssus on Sirius, making him perceive a chasm and stumble toward the fireplace after the spell ended.
• Douglas explained that Temerabyssus reversed perceptions to guide people toward danger and that related versions could make a mount or flying broomstick misinterpret its rider's commands.
• Sirius criticized the spells as more dangerous than dark magic, and Douglas said he kept them sealed because they offended the natural order.
• Sirius asked whether Douglas had used the spell on centaurs, and Douglas ignored the question.