Chapter Summaries

Grindelwald’s operation in the Forbidden Forest alarmed the centaurs, while Li Weide investigated how to keep an Obscurus alive. Li Weide discovered that the Obscurus could consume magical residue, leaving him with a way to feed and preserve it.

• Ogg led Grindelwald to a clearing where wizards prepared a large tent and crates of Dark Creatures.
• Fernandez confronted Ogg about the damage to the forest and the danger the creatures posed, but Ogg urged him not to challenge Grindelwald and promised to report the centaurs’ concerns.
• Slytherin scolded Li Weide for raising only a few dozen chickens at a time, and Li Weide explained that he hoped to breed many Basilisks by finding egg-laying cockerels.
• Li Weide noticed that the Obscurus had regrown where he had cut it and that its preservation spell had weakened.
• Li Weide fed the Obscurus purified residue, which it devoured, and concluded that an Obscurus needed food to survive after losing its host.

Li Weide experimented with the Obscurus and used its magic to make Slytherin a robe that let him touch objects and cast spells again. Slytherin rejoiced at regaining magic, while Li Weide teased him about his suddenly friendly attitude.

• Li Weide found that an Obscurus could rapidly regenerate by absorbing magic, but cutting away more than a third at once drained its main body; he stored it in a Goblin Metal Container and fed it Residue.
• Li Weide discovered that Obscurus magic could wrap around Slytherin's Wand and used that idea to shape the magic into a robe for Slytherin.
• Li Weide brought the robe to Slytherin, who was startled when it let him feel magic and pick up parchment.
• Li Weide gave Slytherin a wand, and Slytherin cast Wingardium Leviosa, rejoicing that he could use magic again.
• Slytherin learned that the robe could last three months with ordinary use and that Li Weide could make another; Li Weide then teased him for smiling and said he preferred his former defiance.

After Slytherin defeated Li Weide in a duel, he explained how ruthless tactics could overcome an opponent with greater magical power. Li Weide eagerly began planning ways to combine Muggle weapons and enchanted ammunition, leaving Slytherin alarmed by the ideas he had inspired.

• Slytherin defeated Li Weide with a Petrification Charm after using lethal curses to control his movements.
• Li Weide realized Slytherin's battle strategy differed from Dumbledore's dueling techniques because Slytherin used ruthless spells to force opponents into mistakes.
• Slytherin described using hidden crossbows and poisoned weapons in his past fights, and Li Weide had an epiphany about using Muggle weapons and Biting Cabbage.
• Li Weide and Slytherin fought for two more hours, and Li Weide replenished the magical power in Slytherin's Wizard Robe with the Obscurus.
• Slytherin showed Li Weide an Anti-Magic Rune for weapon ammunition, and Li Weide wrote down ideas involving enchanted bullets and Basilisk venom.

Li Weide learned that Grindelwald was preparing dangerous assessments involving Dark Creatures and decided to borrow some for his own research. The chapter ended with Tom realizing Li Weide was planning another scheme.

• Li Weide explained to Tom how careful phrasing could persuade House-elves, then complimented Nearly Headless Nick’s beard.
• Tom’s owl Newborn delivered a box from Tom’s father for Li Weide, who pocketed it and promised Tom he had prepared something for him too.
• Annie arrived with news and learned the Whispering Charm from Li Weide, allowing the three of them to communicate secretly.
• Annie told Li Weide and Tom that Grindelwald had set up a Forbidden Forest tent filled with dangerous Dark Creatures and Magical Animals for student assessments.
• Li Weide became eager to take some of the creatures for research and insisted he was borrowing them, while Tom worried about his plan.

Dumbledore negotiated with Fernandez over the centaurs’ concerns about Grindelwald’s camp, but an attack on centaurs forced their leader to mobilize a rescue party. At the camp, Grindelwald learned that his followers could no longer remember the person who had urged them to attack, suggesting that someone unknown had infiltrated the group.

• Dumbledore met Fernandez at the centaur settlement and offered to restore the damaged forest and improve protections against Dark Creatures.
• An injured centaur reported that wizards had attacked and captured Feilun and several others, so Fernandez led his people to rescue them.
• Dumbledore tried to calm Fernandez, then joined the centaurs as they raced toward Grindelwald’s camp.
• Grindelwald questioned the Wizarding Supremacists who had captured the centaurs, but they could not remember the name or appearance of the person who had urged them to attack.

Grindelwald investigated a clash between Wizarding Supremacists and centaurs, but Legilimency showed that every witness had genuine memories that contradicted one another. He asked Dumbledore to examine the Wizarding Supremacists, and Dumbledore was left just as confused.

• Grindelwald questioned Feilun and the Wizarding Supremacists after their accounts of the centaur clash conflicted.
• Grindelwald used Legilimency on the witnesses and found they all had genuine memories, including memories of an extra person who seemed not to exist.
• Grindelwald checked the carriage and tent, discovering that the centaurs' account of released Quintapeds conflicted with what he found there.
• Fernandez arrived with Dumbledore and accused Grindelwald's people of harming the centaurs, while Grindelwald insisted the incident remained unclear.
• Grindelwald invited Dumbledore to examine the Wizarding Supremacists' memories, and Dumbledore also found the situation inexplicable.

Dumbledore and Grindelwald investigated reports of strange visions after the centaurs attacked Grindelwald’s Wizarding Supremacists. Their search uncovered chaotic magic produced by the gathered Dark Creatures, and Dumbledore recognized traces resembling the Ancient Magic he had seen on Li Weide.

• Dumbledore tried to negotiate with Fernandez, but Grindelwald provoked the centaurs until they fired arrows at him and the Wizarding Supremacists.
• Dumbledore knocked the attacking centaurs unconscious and moved them to safety, then argued with Grindelwald about how to deal with them.
• Dumbledore and Grindelwald checked the tents and surrounding area, finding that no Dark Creatures had escaped but that the local magic was unusually chaotic.
• Dumbledore ordered Grindelwald to send the Dark Creatures away and suspend his Educational Reform plan, but Grindelwald refused and suspected Dumbledore of causing the visions.
• Dumbledore privately recognized that the clashing Dark Magic had formed a chaotic new magic resembling the Ancient Magic he had seen on Li Weide.

Li Weide revealed that his rune-enhanced revolvers could shatter Tom’s Shield Charm, then used a remotely controlled Obscurus to investigate Dumbledore’s discovery in the Forbidden Forest. He prepared to bring Slytherin along as the Obscurus drone went to search for clues about the missing senior student and strange magic.

• Li Weide showed Tom and Annie two rune-enhanced revolvers, then demonstrated that a shot could shatter Tom’s Shield Charm and destroy a wooden target.
• Tom took one revolver and ammunition, while Annie declined one for the moment; the three used up the practice targets before leaving the Room of Requirement.
• Dumbledore took Li Weide to his office and explained that Dark Creatures in the Forbidden Forest had gathered and triggered magic resembling Ancient Magic, alongside reports of a nonexistent person and distorted centaur memories.
• Li Weide proposed investigating the Forbidden Forest and used Nightmare Magic to attach part of his consciousness to an Obscurus, controlling it remotely like a drone.
• Li Weide planned to send the Obscurus into the Forbidden Forest and bring Slytherin along to investigate.

Li Weide and Dumbledore used the Obscurus to investigate the chaotic magic above Grindelwald's tent and found a huge concentration of Ancient Magic. When an invisible attacker struck them, their Disillusionment Charms failed and revealed an identical Obscurus.

• Dumbledore let Li Weide send the Obscurus to investigate and shared its senses so he could guide him.
• They flew over Hogwarts and reached Grindelwald's tent, where Li Weide saw Ancient Magic mixed into the Dark Magic gathering there.
• Li Weide and Dumbledore followed the magic vortex above the tent and noticed their vision distort as they drew closer.
• An invisible presence collided with the Obscurus and fired a spell, prompting Li Weide to dodge and counterattack.
• Both Disillusionment Charms failed, revealing that the other presence was an Obscurus identical to theirs.

Li Weide and Dumbledore investigated the identical Obscurus they had encountered, using the Marauder’s Map to search for clues. The map showed a Wizarding Supremacist briefly appearing as multiple identical people, and Dumbledore went to the tent to investigate as Grindelwald approached.

• Li Weide and Dumbledore escaped from the matching Obscurus and discussed whether it was their past selves or an illusion.
• Li Weide checked the Marauder’s Map, but it showed no other versions of him or Dumbledore; Dumbledore noticed the centaurs migrating deeper into the Forbidden Forest.
• Li Weide saw Best William’s name split into two identical names, then briefly into three, before returning to one.
• Grindelwald appeared on the map and hurried toward the Forbidden Forest, so Dumbledore left to investigate while Li Weide stayed behind.

Dumbledore borrowed Li Weide's Marauder's Map after spotting Slytherin's name, while Li Weide hurried him toward the Forbidden Forest to give Slytherin time to clear the Secret Chamber. There, the group witnessed a duplicate Grindelwald wielding the Elder Wand vanish after clashing spells with the real Grindelwald.

• Dumbledore saw Salazar Slytherin's name on the Marauder's Map, borrowed it, and Li Weide realized he might investigate the Secret Chamber.
• Li Weide persuaded Dumbledore to take him to the Forbidden Forest, giving Slytherin time to clear the Secret Chamber and leave with the Little Roosters.
• Grindelwald questioned Best and the Wizarding Supremacists about several brief duplicates of Best, including one that had wounded him with a Cutting Curse.
• Li Weide and Dumbledore learned the duplicate Bests had truly appeared, and Li Weide noticed a multicolored vortex growing above the tent.
• A second Grindelwald appeared and traded Killing Curses with the real Grindelwald before vanishing, and Li Weide revealed that the duplicate had held the Elder Wand.

Li Weide, Dumbledore, and Grindelwald stopped the apparitions of people resembling them by separating the gathered Dark Creatures, then Li Weide proposed that the doubles came from parallel worlds. He explained how altered timelines could create similar but different worlds, leaving Dumbledore and Grindelwald considering the differences between their counterparts.

• Dumbledore confirmed that his Elder Wand was genuine, and Grindelwald realized his double had also wielded a real Elder Wand.
• Li Weide urged Dumbledore and Grindelwald to disperse the Dark Creatures, and Grindelwald agreed to divide them by year and move them apart.
• Li Weide recommended increasing the distance between the Dark Creatures to five hundred meters, and the multicolored vortex dissipated as the strange incidents stopped.
• Li Weide proposed that the doubles came from parallel worlds and used a changed timeline to explain how similar worlds could differ.
• Dumbledore and Grindelwald recognized that the other Grindelwald's Elder Wand and the Besters' different hair colors marked differences between their worlds.

Li Weide, Dumbledore, and Grindelwald investigated how overlapping Parallel Worlds could swap people and erase memories of people or objects that did not exist in their world. After Dumbledore ordered them to stop their research, he found Slytherin missing from the Secret Chamber and discovered fresh chicken droppings inside.

• Li Weide theorized that Dark Creatures could trigger Parallel World overlaps in which people encountered their counterparts.
• Grindelwald realized his friends had been forgetting a mutual friend and found that Gottfried Martin carried a cherry wood wand instead of the Ebony Wand Grindelwald had given him.
• Li Weide proposed that counterparts could be swapped between worlds and that memories of people or objects absent from the new world would gradually fade.
• Dumbledore ordered Grindelwald to scatter the Dark Creatures and told Li Weide to stop investigating Parallel Worlds.
• Dumbledore checked the Marauder's Map, saw that Slytherin had disappeared from the Secret Chamber, and went there to investigate.
• Dumbledore found the Secret Chamber empty except for a fresh pile of chicken droppings.

Li Weide explained that the senior female student's magical riot had caused her body to be swapped with a counterpart from a Parallel World, leaving her soul behind. She learned that the body in the Crystal Coffin was not her original body, though the reason her own body vanished still needed verification.

• Li Weide recounted the Forbidden Forest incident and proposed that the senior female student's missing name might be connected to Parallel Worlds.
• The senior female student revealed that her Nightmare Magic had let her soul leave her body, and that her magic rioted before her consciousness was attacked and her memories vanished.
• Li Weide compared her soul with the body in the Crystal Coffin and found differences in their features, confirming they were not the same person.
• Li Weide explained that the magical riot had opened a passage to a Parallel World, swapping in another version of her body while her original body and soul were separated.
• The senior female student realized that her body had left her behind.

Li Weide and Slytherin investigated the strange events surrounding Slytherin’s vanished remains after Slytherin demonstrated that he could learn a spell invented centuries after his death. They suspected Slytherin might not be an ordinary ghost and wondered whether his physical body was still alive, leaving the mystery unresolved.

• Li Weide woke from a nightmare and found Tom reading in their dormitory; Tom used a Stunning Spell on himself to fall asleep when Li Weide suggested practicing.
• Li Weide visited Slytherin in the Wizard Tower and told him about the strange events and Dumbledore discovering him.
• Li Weide noticed Slytherin was reading a book containing spells from a later era, and Slytherin demonstrated one by melting a wooden target into black slime.
• Li Weide pointed out that ghosts could not learn new knowledge, prompting Slytherin to wonder whether he had ever truly died.
• Li Weide and Slytherin considered whether Slytherin’s remains had never been in the coffin and whether his body might still be alive as part of an experiment.

Li Weide and Slytherin investigated Slytherin’s grave and discovered that the empty stone coffin may have been used to seal Slytherin’s soul. Ancient Magic in the tomb suggested that an Ancient Sage might have been involved, but Slytherin had forgotten the sage’s identity and insisted the sage would never have done it.

• Slytherin dug up his grave with Li Weide and found that the stone coffin was empty.
• Li Weide uncovered incomplete runes in the coffin, and Slytherin recognized them as roughly a thousand years old.
• Li Weide proposed that the coffin had sealed Slytherin’s soul rather than held his body, and Slytherin agreed that the idea fit his memories.
• Li Weide found traces of Ancient Magic in the tomb’s bricks and asked whether the Ancient Sage from Slytherin’s era could have built it.
• Slytherin admitted that he had forgotten the sage’s name and details, but maintained that the sage would never have sealed his soul there.

Li Weide helped Slytherin use a modified Obscurus garment to regain a solid outer body, and Slytherin revealed his plan to leave Hogwarts and investigate the truth about his past. Dumbledore discovered them in the Forbidden Forest, and the three prepared to share their stories.

• Li Weide finished modifying the Obscurus garment, allowing Slytherin to touch objects and use magic with a solid outer shell.
• Slytherin told Li Weide he planned to leave Hogwarts and investigate the truth himself, despite the war outside.
• Slytherin and Li Weide sensed someone behind them in the Forbidden Forest and turned to find Dumbledore.
• Dumbledore explained that he had expanded the Marauder's Map to cover the Forbidden Forest and had found both of them.
• Slytherin admitted he had asked Li Weide to keep his existence secret, while Dumbledore questioned how he could appear so alive as a ghost.
• Li Weide accepted that Dumbledore had discovered the Wizard Tower, and Dumbledore asked to hear their story.

Dumbledore learned that an unknown enemy tied to Ancient Magic threatened Li Weide and agreed with Slytherin that the boy needed protection. The chapter ended with Slytherin entrusting Tom to Dumbledore for training alongside Li Weide.

• Li Weide transformed his laboratory into a sitting room and explained that Toby had given him the house.
• Slytherin asked Dumbledore to protect Li Weide from the people behind the scheme involving Ancient Magic.
• Slytherin admitted Li Weide had changed his views about Muggle-born students and said he planned to revisit places from his past for clues.
• Dumbledore decided Li Weide needed stricter training, while Slytherin warned that his own methods would be harsher.
• Li Weide suggested Tom join the training, and Slytherin asked Dumbledore to take his descendant under his guidance.

Tom and Li Weide endured Dumbledore’s brutal dueling practice, then gained permission to use Slytherin’s Study as a shared laboratory. After setting up the underground space, Li Weide began raising chickens and hinted at plans for a Basilisk, leaving Tom alarmed.

• Tom freed himself from the arena wall and joined Li Weide in fighting Dumbledore, and the three sparred until Tom and Li Weide were exhausted.
• Dumbledore assigned Tom and Li Weide reflection essays and told them to return for more training the next day.
• Li Weide told Tom that Dumbledore had approved Slytherin’s Study as their laboratory, where they divided the underground chamber between plants and spell practice.
• Dumbledore and Headmaster Dippet discussed protecting Li Weide and trying to keep Slytherin from siding with Grindelwald.
• Tom found Li Weide raising chickens in the study and realized Li Weide might be planning to raise a Basilisk underground.

Li Weide reassured Tom that he would raise a Basilisk somewhere legal, then worked on Newt’s suitcase while Slytherin reconsidered his views of Muggles. After resting, Tom went with Li Weide to Hogsmeade and found Dumbledore waiting at the Hog’s Head.

• Li Weide told Tom he planned to breed a Basilisk outside Hogwarts and said he would use chickens and toads as cover for his experiments.
• After Tom left, Li Weide entered Newt’s suitcase and began changing its projected grassland environment.
• While flying through a Muggle world scarred by bombing, Slytherin reflected on the destructive power Muggles had developed and reconsidered his opinions of them.
• Tom slept until noon after days of training, then ate the food Li Weide brought him and learned that Dumbledore had given them the day off from special training.
• Li Weide took Tom through the Secret Passage to Hogsmeade, explaining that Dumbledore had permitted him to visit Aurelius and would not mind Tom accompanying him.
• At the Hog’s Head, Tom tried to flee when he saw Dumbledore, but Li Weide blocked him and brought him inside; Tom blamed Li Weide for bringing him.