Chapter Summaries

In 1991 London, Gavin Gu received an acceptance letter to Hogwarts, revealing that the world he had thought ordinary was the Harry Potter world. He decided to secure his parents’ approval by proving himself academically, starting with a plan to go straight to Oxford before attending Hogwarts.

• Gavin finished his morning lessons and Meditation, then complained about the dull British lunch Mrs. Carlos served.
• A grey owl flew into the dining room, drank Gavin’s juice, and delivered a letter addressed to him.
• Gavin recognized the Hogwarts crest on the envelope and hid the letter from Mrs. Carlos.
• After Mrs. Carlos chased the owl away, Gavin decided he would attend Hogwarts but needed a way to convince his parents.
• Gavin opened the letter from Minerva McGonagall, learned term began on September 1, and resolved to start by aiming for Oxford.

Gavin called his parents to tell them he planned to study at Oxford, then persuaded Professor Bill Roscoe to accept him as an eleven-year-old doctoral student with a full scholarship. After Gu Jianguo and Lin Wanyin verified his admission and visited Oxford, Gavin began work with Professor Bill and left his Hogwarts letter waiting in a drawer.

• Gavin told Lin Wanyin that he was nearly ready to attend Oxford, prompting Gu Jianguo to book a flight to the United Kingdom.
• Gavin met Professor Bill Roscoe at Oxford and presented a proposal for decentralized systems and blockchain, persuading him to take Gavin on as a doctoral student with a full scholarship.
• Gu Jianguo and Lin Wanyin returned, confirmed Gavin's Oxford admission with Professor Bill, and celebrated the news.
• Gavin took his parents to Oxford, where Professor Bill reassured them that he would look after Gavin.
• After Gu Jianguo and Lin Wanyin left, Gavin urged Professor Bill to begin work on the paper immediately.
• Gavin looked at his Hogwarts acceptance letter and said he would go there once matters at Oxford were settled.

Gavin established his academic credentials by rapidly producing research papers on distributed consensus, leaving Professor Bill to handle their publication. With Bill granting him a long break, Gavin left Oxford and set off for the magical world.

• Gavin showed Professor Bill his research framework and agreed to turn it into papers within two weeks.
• Gavin submitted a new paper each day, leaving Professor Bill increasingly exhausted by the growing stack of manuscripts.
• Gavin completed the outline of his tenth paper and asked to take a break.
• Professor Bill urged Gavin to leave for several months and promised to manage the papers and their publication.
• Gavin left Oxford, satisfied with his progress, and headed toward the magical world.

Gavin met Professor McGonagall and explored the wizarding world for the first time, buying his school supplies and discovering that he could adapt unusually well to different wands. He stayed at the Leaky Cauldron rather than risk another Knight Bus ride, pondering how consciousness might shape a wand’s connection to its wizard.

• Gavin showed Professor McGonagall his guardianship and academic documents, and they took the Knight Bus to the Leaky Cauldron.
• Professor McGonagall revealed Diagon Alley to Gavin, and they exchanged his money at Gringotts before shopping for Hogwarts supplies.
• Gavin tested many wands at Ollivanders before choosing a rigid black walnut wand with a dragon heartstring core, and Ollivander called his adaptability dangerous.
• Gavin told Professor McGonagall that a wand felt like an extension and amplifier of his arm, then chose a hardy-looking toad as a pet.
• Gavin decided to stay at the Leaky Cauldron to avoid riding the Knight Bus again and wondered whether a wizard’s consciousness determined their bond with a wand.

At the Leaky Cauldron, Gavin used meditation to successfully cast Lumos and began investigating how magic worked. He ended the night with hypotheses linking magic to the brain and a possible Fifth Fundamental Force, eager to study magic at Hogwarts.

• Gavin unpacked his school supplies in his room above the Leaky Cauldron and considered what he had learned about magic.
• Gavin studied The Standard Book of Spells, Grade 1 and identified the wand, incantation, movement, and caster's will as parts of spellcasting.
• Gavin used meditation to sense a change in his brain and successfully cast Lumos after his first attempt failed.
• Gavin wrote theories that magic came from the brain, that wands regulated its output, and that magic might be a Fifth Fundamental Force.
• Gavin speculated about Wandless Magic and whether controlled magic compression could be related to an Obscurus, then noted that Lumos seemed to calm him.
• Gavin extinguished Lumos, went to sleep, and hoped Hogwarts would give him answers.

Gavin explored Diagon Alley for a contact who could supply books unavailable through ordinary shops, and struck a deal with Mundungus Fletcher. After studying one of the books and gathering more forbidden texts, Gavin resolved to act sooner on his personal-safety plans; with August 31 ending, he was set to begin at Hogwarts the next day.

• Gavin lingered in the Leaky Cauldron to overhear complaints and learn that valuable research materials were sold on the black market.
• Gavin found Mundungus Fletcher peddling fake magical goods and offered him five Galleons as a deposit for books unavailable at school.
• Gavin identified himself as Gu Wen, asked Mundungus to bring what he could obtain, and warned that he would report any missing books to Dumbledore.
• Gavin read Wizard Body Structure, which described experiments on a wizard's body and supported his hypothesis that wizards and Muggles shared mostly the same physical structure.
• Gavin stored the books Mundungus had brought in an enchanted bag and decided to put his personal-safety plans into action sooner.
• Gavin saw that it was August 31 and looked forward to starting at Hogwarts the next day.

Gavin traveled to Hogwarts for his first year, passed through the hidden platform at King’s Cross, and met Cedric Diggory and Cho Chang aboard the Hogwarts Express. As the train arrived after dark, Gavin prepared to leave with the new students for the school and its Sorting Ceremony.

• Gavin watched the Weasley family and Harry Potter pass through the barrier between Platforms 9 and 10, then crossed it himself to reach the Hogwarts Express.
• Gavin found Cedric Diggory and Cho Chang in an empty compartment, and the three introduced themselves and began talking.
• Gavin and Cho bonded over their dislike of British food and listed Eastern dishes while Cedric listened and defended some local favorites.
• Cedric and Cho told Gavin about Hogwarts routines, Quidditch, and the Sorting Ceremony, while Gavin questioned Quidditch’s rules and joked about choosing a house near the kitchen.
• As the train arrived at night, Cedric and Cho told Gavin to follow the other new students after they got off, and Gavin saw the dark station through the steam.

Gavin arrived at Hogwarts, chose Hufflepuff over the Sorting Hat’s recommendation of Slytherin, and settled into his dormitory. After everyone fell asleep, he sneaked into the kitchens, intent on improving Hogwarts food.

• Gavin followed Hagrid across the lake and entered Hogwarts with the first-years.
• Gavin persuaded the Sorting Hat to place him in Hufflepuff, where he joined Justin Finch-Fletchley and Ernie Macmillan at the feast and in their dormitory.
• Gavin considered how Hogwarts meals could be improved and learned the kitchen’s entrance was hidden behind a fruit painting.
• After his roommates fell asleep, Gavin snuck into the kitchen and announced his plan for a culinary revolution.

Gavin shared Chinese breakfast with Cho Chang and Cedric before heading to his first Transfiguration class, where his unusual skill and questions impressed Professor McGonagall. The lesson left him absorbed in the deeper principles of permanent Transfiguration and eager to explore magic beyond the basics.

• Gavin shared rice noodle rolls and boat congee with Cho Chang and Cedric, and Cho tasted the rolls from her childhood.
• Gavin walked with Ernie Macmillan and Justin Finch-Fletchley to their Transfiguration classroom.
• Professor McGonagall transformed from a tabby cat and began the first lesson by teaching the students basic Transfiguration.
• Gavin turned his match into a silver needle and then shrank it, earning ten points for Hufflepuff.
• Gavin asked Professor McGonagall about permanent Transfiguration, and her explanation left him contemplating its deeper principles.

Gavin excelled at his first Charms lesson, learning how the Levitation Charm related to spells that affected weight and movement. After lunch, he found the Room of Requirement on the Seventh Floor and opened a room where he could practice magic in peace.

• Professor Flitwick taught the first-years the Levitation Charm, and Gavin made his feather float steadily on his first attempt.
• Gavin asked Professor Flitwick about controlling levitation, casting on living targets, and spells that made objects heavier; Flitwick explained the Slowing Charm and the Impediment Jinx.
• Professor Flitwick praised Gavin's questions and awarded Hufflepuff five points.
• After lunch, Gavin went alone to the Seventh Floor and walked three times past the wall opposite the Barnabas tapestry while wishing for a quiet place to practice.
• A door appeared in the wall, and Gavin opened the Room of Requirement.

Gavin used a hidden stone chamber to practice magic and investigate the limits of Transfiguration. After testing several transformations, he suspected that Gamp's Law reflected the limits of wizards' understanding rather than an absolute prohibition, leaving him eager to explore that possibility.

• Gavin entered the spacious stone chamber and practiced the Levitation Charm, adjusting a feather's height, stability, and movement.
• Gavin transformed a matchstick into a silver needle, then broke it and discovered that the needle reverted to pieces of the original matchstick.
• Gavin reviewed Gamp's Five Exceptions and considered whether damaged transformations revealed why food could not be conjured.
• Gavin transformed a matchstick into a shrimp snack stick and found that breaking it exposed the matchstick inside.
• Gavin wrote down his observations and proposed that wizards could only transform objects into things they understood, concluding that Gamp's Law might describe their limits of knowledge.

During his first week at Hogwarts, Gavin earned Hufflepuff points with sharp answers and steady flying, then used Lumos to help Professor Sprout rescue a Gryffindor student from Devil's Snare. The week ended with Gavin continuing to secretly practice spells in the Room of Requirement while Harry, Ron, and Hermione noticed him.

• Gavin practiced spells in the Room of Requirement each day and answered Professor Quirrell's question in Defense Against the Dark Arts, earning two points for Hufflepuff.
• Gavin asked Professor Binns about goblin property rights and Gringotts contracts in History of Magic, earning another point for Hufflepuff.
• Gavin performed well in Flying Class, summoning his Broomstick on the first try and earning points from Madam Hooch.
• When a Gryffindor student was trapped by Devil's Snare, Gavin cast Lumos to make the vines recoil, helping Professor Sprout free the student and earning five points.
• Harry, Ron, and Hermione noticed Gavin after the rescue, while Gavin later continued his spell studies and concealed his evening visits to the Room of Requirement from Ernie and Justin.

Gavin attended his first Potions Class with Professor Snape and successfully brewed a Cure for Boils with Ernie, earning an unexpected point for Hufflepuff. He left the Dungeon Classroom more interested in Potions and its precise procedures, while Justin and Ernie marveled at Snape awarding a point.

• Professor Snape introduced Potions as a precise craft, took attendance, and assigned the first-years to brew a Cure for Boils.
• Gavin and Ernie carefully prepared their ingredients while Snape challenged Gavin about watching the potion instead of stirring it.
• Justin’s potion bubbled too early and erupted into green foam, earning him a five-point deduction from Snape.
• Gavin and Ernie added porcupine quills after removing their potion from the heat, producing a successful pink brew.
• Snape judged Gavin’s potion acceptable and awarded Hufflepuff one point, astonishing the class.
• After class, Justin and Ernie discussed Snape’s rare point award while Gavin reflected that Potions was more interesting than he had expected.

At dinner, Gavin’s Hufflepuff classmates celebrated his Potions point and discovered that his shredded potatoes tasted unlike any potatoes they had known. Hermione introduced herself by declaring she would overtake him in points, while Harry and Ron befriended Gavin; the chapter left Hermione studying to make good on her challenge.

• Ernie announced that Snape had awarded Gavin a point for Hufflepuff in Potions, and the students marveled at the rare recognition.
• Cedric tried Gavin’s shredded potatoes, was astonished by their taste, and accepted that they were potatoes.
• Hermione told Gavin she would soon overtake him in points, and Gavin welcomed the competition.
• Harry and Ron explained Hermione’s intense concern about grades, then praised Gavin and said they wanted to get to know him.
• Hermione returned to the Gryffindor table and opened a book to begin working toward beating Gavin.

Hermione tried to close the House Points gap with Gavin, while he focused on Transfiguration and made chopsticks that startled his classmates. After hearing that Gryffindor had a Nimbus 2000, Gavin agreed to coach Cedric in Quidditch and planned to assess Hufflepuff's team at practice.

• Hermione worked harder to earn House Points, but Gavin continued accumulating them steadily without noticing her pursuit.
• Gavin practiced partial Transfiguration in the Room of Requirement and made wooden chopsticks for himself.
• Cedric told Gavin that Gryffindor's new Seeker had a Nimbus 2000, leaving Hufflepuff worried about its chances in Quidditch.
• Gavin claimed he could catch the Golden Snitch within five minutes and explained that he viewed Quidditch as a problem to solve.
• Cedric asked Gavin to coach him, and Gavin agreed in exchange for six books and under conditions for training.
• Gavin planned to attend Hufflepuff's practice the next afternoon to assess the team's abilities.

Gavin stumbled upon Harry, Ron, and Hermione confronting a troll in the Girls' Bathroom and killed it with powerful Transfiguration after Ron's spell faltered. Gavin collapsed from exhausting his Magic, and Snape warned that he might die if they did not act quickly.

• Gavin met Harry and Ron, who were rushing to warn Hermione that a troll was loose.
• Gavin entered the Girls' Bathroom, where his fallen door distracted Ron and disrupted the Levitation Charm aimed at the troll's club.
• The troll charged Gavin, who bound its legs with a transformed vine and slowed its fall with Gravipressus.
• Gavin transformed the floor into a stone spike that pierced the troll's eye and killed it, then collapsed from magical exhaustion.
• The teachers arrived to find the troll dead and Gavin unconscious, and Snape warned that Gavin might die without immediate help.

At Hogwarts, the professors argued over whether Gavin Gu should be expelled for killing a troll, but Dumbledore chose to wait until Gavin recovered before speaking with him. Gavin woke at St Mungo's and met a fragile-looking girl whose immense destructive power unsettled him, and she asked if he was dying too.

• Snape demanded that Gavin be expelled, while McGonagall and Sprout defended his actions as necessary to save Harry Potter, Hermione Granger, and Ron Weasley.
• Dumbledore said he had seen the students' memories and agreed Gavin had acted only when the troll threatened them, though his unusual understanding of magic concerned him too.
• Dumbledore refused to expel Gavin before hearing his account and said the staff first needed to know whether he would survive.
• Snape explained that Gavin had been taken to St Mungo's because Hogwarts' Hospital Wing could not treat him, and the professors waited for news.
• Gavin woke at St Mungo's and sensed immense, destructive darkness inside the silver-blond girl sitting beside his bed.
• The girl asked Gavin, "Are you... dying too?"

While recovering at St. Mungo's, Gavin Gu befriended Cordelia Rowle, a girl who had been hospitalized for five years. When Cordelia nearly lost control of the Obscurus inside her, Gavin stayed curious rather than fleeing, and Dumbledore arrived as her bracelet suppressed it.

• Gavin Gu met Cordelia Rowle, who said she had been in St. Mungo's for about five years and that her father had not visited since leaving her there.
• Cordelia wheeled Gavin through the hospital and told him that her mother had died and that her family had often argued about the dead and the living.
• Cordelia's distress caused an Obscurus to emerge, but the silver bracelet on her wrist forced it back under control.
• Gavin calmly asked Cordelia about the Obscurus, surprising her because he showed curiosity instead of fear.
• Dumbledore arrived in the courtyard and checked on Cordelia and the bracelet.

Dumbledore explained how Cordelia Rowle’s childhood trauma created her Obscurus and told Gavin he could return to Hogwarts after recovering. When Gavin was discharged from St. Mungo’s, Cordelia finally emerged after he left and found the book and note he had left for her.

• Dumbledore recounted Cordelia’s painful childhood, the loss of her family, and how Nicolas and he created a bracelet that could temporarily suppress her Obscurus.
• Dumbledore told Gavin that Hogwarts would not expel him for protecting other students, despite some professors’ reservations.
• Gavin tried repeatedly to visit Cordelia, but she avoided him, so he sat outside her room and told her stories about Hogwarts.
• On the day he was discharged, Gavin said goodbye outside Cordelia’s silent room and left without opening the door.
• After Gavin’s footsteps faded, Cordelia entered his former room and found Sapiens: A Brief History of Humankind with his note explaining that people, not magic, were the problem.

Gavin returned to Hogwarts after recovering from his illness and was welcomed by Hufflepuffs, Harry, Ron, and Hermione. As he resumed classes and promised to help Cedric train for Quidditch, he began a new research project aimed at saving the host of an Obscurus.

• Ernie and the Hufflepuffs welcomed Gavin back, and Harry, Ron, and Hermione thanked him for saving them from the troll.
• Fred and George met Gavin, while Cedric admitted he was worried about facing Harry and his Nimbus 2000; Gavin agreed to resume training Cedric.
• Gavin returned to classes, earned points from several professors, and lost five Hufflepuff points when Snape criticized his potion preparation.
• Gavin went to the Room of Requirement, cleared his old notes from the blackboard, and wrote a new research proposal for stopping an Obscurus from draining its host's life.