Chapter Summaries

Regulus asked Professor Slughorn what could cause drastic changes in a wizard’s appearance, and Slughorn explained how irreversible magical transformations could alter a person from within. Regulus concluded that Voldemort’s soul had likely undergone destructive fission while his own soul was growing through fusion, then left Slughorn’s office after receiving a warning to avoid irreversible things.

• Regulus asked Slughorn about causes of drastic changes in appearance, hoping to learn whether soul magic could be involved.
• Slughorn described corrosive Dark Arts objects, advanced curses, rituals, and fundamental magical transformations as possible causes.
• Slughorn used Felix Felicis’s irreversible transformation as an analogy and warned Regulus that some changes could not be undone.
• Regulus reconsidered Voldemort’s shattered soul as a new structure formed through fission and viewed his own expanding starry soul as growth through fusion.
• Regulus thanked Slughorn and left for a meal after Slughorn told him to stay away from irreversible things.

Regulus watched Baruk demonstrate how its Fire Affinity was changing its silk, then learned that Baruk considered him and his friends its colony. In the Library, he found Lily waiting and opened their conversation by asking if her house had lost power.

• Hermes sent a small fireball at Baruk, whose web held it briefly as Regulus observed the Fire Affinity spreading into its silk-gland branch.
• Avery said his father had rejected his request to raise an Acromantula, while Regulus considered the trouble Baruk might cause if it were seen around Hogwarts.
• Baruk panicked when Regulus asked if it wanted to return to the Forbidden Forest, then explained that it wanted to grow strong enough to challenge Aragog and called Regulus its leader and the group its colony.
• Regulus left Baruk on his pillow and went to the Library to read a basic book on Alchemy.
• Regulus found Lily waiting at their usual table, cast a Muffling Charm, and asked if her house had lost power.

In the Library, Regulus eased Lily’s frustration by listening to her describe how the power crisis affected her family, then apologized for not writing over the holiday. They exchanged a Christmas gift and parted on warm terms, while Regulus remembered a magical experiment he had neglected to resume.

• Lily told Regulus that power cuts and shortages were affecting her family and neighbors, and demonstrated wandless magic by folding parchment into a Paper Crane.
• Regulus apologized for forgetting to write to Lily over the holiday, and she teased him for drawing her into a long conversation before apologizing.
• Lily asked whether Regulus had been hurt in the fight and house fire Marcia had mentioned, and he said it was a family matter.
• Regulus remembered his failed attempts to merge space into his Guardian Image and considered trying again outside Hogwarts.
• Lily gave Regulus a handmade Slytherin-colored star ornament for Christmas, and he tucked it over his heart.
• Lily and Regulus forgave each other, wished each other good night, and left the Library for their respective towers.

During Herbology, Regulus studied how Poison Tentacle venom spread through the body and connected its diffusion pattern to a possible way to restore Avada Kedavra’s original healing purpose. After class, Professor Sprout noticed his observations and asked what he had seen.

• Professor Sprout taught the students to protect themselves with HerbaProtego and Dragon-hide Gloves before trimming Poison Tentacle’s dead vine tips.
• Regulus examined the plant’s Magic Power while Avery struggled with his oversized gloves and pruned beside him.
• Colin Macmillan was grazed by a Poison Tentacle vine, and Professor Sprout froze the vine and treated his wrist while Gareth Diggory pulled him back.
• Regulus observed the venom spreading through Macmillan’s neural network and considered whether that diffusion could help Avada Kedavra target diseased tissue without harming healthy tissue.
• After class, Professor Sprout found Regulus watching the Poison Tentacle’s Magic Power and asked him what he had seen.

Regulus showed Professor Sprout the spell he had developed from the Whomping Willow’s attack mechanism, and she praised its usefulness while reminding him that he could choose what to destroy. After he admitted that one ancient Whomping Willow at the Black family’s Plantation was badly weakened by his research, Sprout agreed to visit and help it recover.

• Regulus demonstrated his oscillation-stacking spell by silently shattering a dried vine tip, and Professor Sprout recognized that it could also loosen compacted soil.
• Professor Sprout reminded Regulus that controlling a destructive spell meant choosing what not to break, and Regulus connected her advice to Professor Slughorn’s warning about irreversible consequences.
• Regulus looked at the Sunlight Ebony Shrub, but Professor Sprout told him he was not ready to handle it, and he accepted her judgment.
• Regulus told Professor Sprout that extracting Magic Power had nearly stopped a Whomping Willow’s circulation, though Natural Magic Power had restarted it and new buds had appeared.
• After hearing that the injured tree was an ancient specimen from the Bulgarian Magical Reserve at the Black family’s Cornwall Plantation, Professor Sprout agreed to examine it on Saturday afternoon, and Regulus arranged to collect her at two o’clock.

Regulus explained how he used Avery and Alex to screen the pure-bloods seeking the Black family’s favor, then brought Hermes to the Room of Requirement to demonstrate a Fiendfyre transformation. Hermes survived Regulus’s Flame Whip but was thrown into a Training Dummy, and he demanded to know why Regulus had used Fiendfyre against him.

• Regulus let Avery handle dealings with prominent pure-blood families and Alex handle smaller ones, while he met only those worth his attention.
• Hermes asked Regulus what he had used at the Lestrange family estate, and Regulus invited him to the Room of Requirement to try it.
• In the Training Ground, Regulus formed a long black Flame Whip from a Fiendfyre transformation and struck it near Hermes, sending a sonic boom through the room.
• Regulus cracked the whip at Hermes’s Shield Charm, exploiting a weak point so the impact passed through and hurled Hermes into a Training Dummy.
• Hermes, unharmed but shaken, asked what the spell was, then protested that Regulus had used Fiendfyre against him.

Regulus refused to teach Hermes Fiendfyre and explained that he needed to strengthen his mental discipline and control of Magic first. After demonstrating how easily he could enter Hermes’s undefended mind, Regulus set out training in Legilimency and wandless Magic Manipulation, then told Avery and Alex to practice as well.

• Hermes asked Regulus to teach him Fiendfyre, but Regulus refused because Hermes was not ready to control it safely.
• Regulus explained that Hermes’s main weakness was his lack of mental strength, emotional control, and precise Magic Manipulation, and offered him a choice between continuing the Dark Arts or training those fundamentals.
• Hermes chose to follow Regulus’s training and asked about learning a Patronus, but Regulus put that off and began explaining Legilimency.
• Regulus used Legilimens to show Hermes that his mental defenses were almost nonexistent, without searching his memories.
• Regulus assigned Hermes regular Legilimency defense practice and wandless Magic Manipulation, then told Avery and Alex to try the exercises too.

Regulus tested Hermes, Avery, and Alex’s defenses against Legilimency, then assigned them training and used Baruk to make Avery and Alex practice combat. After an exhausting session, Hermes walked back with the others, wondering whether he was happy.

• Regulus found that Hermes had the strongest mental defenses, while Avery and Alex could barely sense or resist Legilimency, and he assigned them different training.
• Regulus enlarged Baruk into an adult Acromantula and told him to chase Avery and Alex instead of biting them.
• Baruk outran Avery and Alex, broke their Shield Charms, and cocooned them in webbing while repeatedly calling them little spiders.
• Avery and Alex tried splitting up to evade Baruk, but he swung from the ceiling and caught them both as Hermes practiced building a mental barrier.
• After more than two hours, the exhausted group left the Room of Requirement, and Hermes wondered whether he was happy.

Regulus met Lina and Samuel in the Library, where they delivered the Muggle-world textbooks he had requested and accepted that their delay meant they would receive no reward for their part in the Lestrange affair. After they left, Snape watched them from the shadows.

• Regulus realized Lina and Samuel were using formal channels to establish their places in his growing group.
• Lina and Samuel brought Regulus books on Aerodynamics, Wave Mechanics, Optics, and Jet Propulsion, explaining that a Library power outage had made it easy to retrieve them.
• Regulus praised them, then raised the Lestrange affair; Lina and Samuel understood that their delayed delivery had cost them any reward.
• In the corridor, Lina told Samuel that she had not expected Regulus to believe their excuse and accepted that the reward was gone.
• Snape watched Lina and Samuel walk away from the shadows.

Regulus accompanied Professor Sprout to the Black family’s Plantation in Cornwall, where she examined a damaged Whomping Willow. At the cliffs, Regulus discovered that the Starry Sky Kite could open passages through natural space, unlike at Hogwarts, and let it fly over the sea.

• Regulus told Professor Slughorn he was leaving for Cornwall with Professor Sprout and received permission.
• Regulus and Professor Sprout Apparated to the Plantation, where Agnes welcomed them and led them to the Whomping Willows.
• Professor Sprout soothed both trees and examined the damaged one while Regulus went to the cliffs.
• Regulus released the Starry Sky Kite and found that it could open passages through space outside Hogwarts.
• Regulus watched the Starry Sky Kite trace glowing paths through the air and let it fly out over the sea.

Regulus merged his Guardian Will with natural space and created a stable spatial channel, then redesigned his Fiendfyre flight device for controlled, aerodynamic flight. He began accelerating over the sea, testing how fast the improved craft could go.

• Regulus merged his Guardian Will with the space around him and found that it accepted his spatial magic without resistance.
• Regulus placed two anchors fifty meters apart, opened a silver-white channel between them, and crossed through it in a single stride.
• Regulus considered the channel’s potential as a private teleportation network, then removed the anchors and closed it.
• Regulus shaped a new Shield Charm shell with airfoil wings, stabilizers, adjustable slits, and protective charms for a second Fiendfyre flight.
• Regulus launched from the cliff, made smooth turns and a controlled dive, then pulled up and began accelerating.

Regulus tested his Flying Device by breaking the sound barrier and hovering above the clouds before returning to Cornwall. He and Professor Sprout then prepared to take the recovering Whomping Willow back to Hogwarts.

• Regulus adjusted the Flying Device’s wings and Fiendfyre output, broke the sound barrier, and climbed above the clouds with Baruk.
• Regulus hovered above the clouds with Baruk and the Starry Sky Kite before diving back toward Cornwall and landing near the cliffs.
• Regulus returned to Professor Sprout, who explained that the Whomping Willow’s roots were repairing their Magic Circuit, though one section needed correction.
• Regulus suggested taking the Whomping Willow to Hogwarts, and Professor Sprout agreed and levitated its root ball from the ground.
• Professor Sprout and Agnes discussed work on the Greenhouse’s Temperature-Maintaining Charm, then Regulus and Professor Sprout Apparated to Hogwarts.

Professor Sprout replanted the Whomping Willow and showed Regulus that it had grown new circuits from the Natural Magic Power he gave it. Regulus considered using that exchange to imprint plants on a larger scale, then left to find dinner while Dumbledore remained away from Hogwarts.

• Professor Sprout replanted the Whomping Willow behind Greenhouse No. 4 and nourished it with her Magic Power.
• Regulus sensed that the Willow had grown new circuits from his Natural Magic Power and watched a branch recognize him without striking.
• Professor Sprout explained that the Willow had remembered what Regulus gave it and grown in response.
• Regulus wondered whether he could use Natural Magic Power to imprint plants, rebuild a small area, and eventually make an ecosystem work with him.
• Professor Sprout told Regulus to plant first and seek the headmaster's approval when Albus returned.
• Regulus watched Sprout enter the Greenhouse, then realized he had not eaten dinner.

Regulus tested whether he could open a Spatial Channel into Hogwarts and found that the Castle rejected Guardian Will. At the Forbidden Forest boundary, he met Professor McGonagall, who confirmed Dumbledore was away and passed on a message that Regulus knew how to find him.

• Regulus watched James Potter, Sirius, Lupin, and Peter Pettigrew sneak out toward the Whomping Willow on the Full Moon.
• Regulus tested Spatial Channels at the Castle boundary, but Hogwarts stripped away Guardian Will and rejected the attempt to connect a channel inside.
• Professor McGonagall appeared beside an old oak and reprimanded Regulus for being out after curfew.
• McGonagall praised Sirius's progress in Transfiguration, and Regulus thanked her for helping him.
• McGonagall told Regulus that Dumbledore was not at Hogwarts and had said Regulus knew what to do if he wanted to find him.
• Regulus understood that he could use the phoenix feather to summon Fawkes, then returned to the Castle with Baruk.

As the wizarding world’s growing violence and political unrest seeped into Hogwarts, Regulus’s quiet presence kept Slytherin’s Pure-blood tensions from boiling over. He went to visit the Whomping Willow, then spotted Sirius and Eleanor Bones working in Greenhouse No. 3 and secretly approached to watch them.

• The Daily Prophet praised Minister Harold Minchum’s promises of peace while suppressing reports of a Cotswolds family’s murder, and the Muggle world struggled with strikes, inflation, and unemployment.
• Pure-blood talk and extremist symbols resurfaced among Slytherin students, but Regulus’s uncertain position kept the unrest subdued while Slughorn monitored the House.
• Regulus headed to Greenhouse No. 4 to give the Whomping Willow Natural Magic Power, but the smell of Professor Sprout’s fresh Dragon Dung Fertilizer stopped him.
• Regulus noticed Sirius and Eleanor Bones in Greenhouse No. 3, used an Improved Disillusionment Charm to approach them, and saw that they wore earmuffs while working near Mandrakes.

Regulus watched Sirius and Eleanor quarrel over stolen Mandrake leaves, then heard Eleanor complain that Sirius had taken seven leaves from her. Regulus teased her about Sirius singling her out, leaving her furious and promising to use her wand if he stole from her again.

• Sirius and Eleanor fought over Mandrake leaves in Greenhouse No. 3 while Regulus watched unseen.
• Eleanor left the greenhouse, and Regulus reflected on her straightforward nature and Sirius’s growing interest in her.
• Eleanor found Regulus by the Black Lake and complained that Sirius had stolen three more leaves, bringing the total to seven.
• Regulus offered to talk to Sirius and suggested that he trade for the leaves, then asked Eleanor why Sirius only stole from her.
• Eleanor assumed Sirius thought she was easy to bully and warned that she would use her wand if he touched her Mandrakes again.
• Regulus watched Eleanor stride away and told Baruk that she would probably be a Black someday.

Snape chose the Silver Moon Potions contract after confirming the Lestranges no longer posed a threat at Hogwarts, then met Regulus and discreetly showed his supplier badge. Later that evening, Regulus waited in the Abandoned Classroom, where Lily arrived and greeted him as “Professor Regulus.”

• Snape watched Rababstan for two weeks and confirmed that the Lestrange threat at Hogwarts had faded.
• Snape signed the Silver Moon contract and obtained its supplier badge.
• Snape met Regulus in the Corridor, revealed the badge inside his collar, and left without discussing his choice.
• Regulus reflected that Snape had chosen to cooperate with the Blacks while preserving his independence.
• Regulus waited in the Abandoned Classroom, and Lily arrived and greeted him as “Professor Regulus.”

Lily returned to the Abandoned Classroom and tested her improved spellwork against Regulus, who praised her progress and offered advice. Afterward, she met Regulus's lively pet spider, Baruk, and warmed to him, promising to bring Nox next time.

• Lily and Regulus warmed the Abandoned Classroom with a Temperature-Maintaining Charm and prepared for a training test.
• Lily attacked Regulus with layered spells and combinations, forcing him to move while he defended without taking the initiative.
• Regulus praised Lily's improved tactics and pointed out moments when hesitation and an early Shield Charm weakened her performance.
• Baruk crawled toward Lily, startling her until Regulus introduced the spider as his pet.
• Lily cautiously touched Baruk, found him cute, and promised to bring Nox next time.

Lily practiced the Patronus Charm and discussed how her desire to remain close to Petunia could guide her magic. Regulus encouraged her to learn more about herself and the world, and Lily left determined to keep practicing.

• Lily summoned a dense Silver Light Patronus that lasted nearly half a minute, showing progress without yet taking a corporeal form.
• Regulus explained that Lily's desire-based approach was slower than using happy memories but could produce a stronger Patronus.
• Lily told Regulus she thought of Nox and a memory of naming the cat with Petunia, explaining that she feared losing her sister because of magic.
• Regulus told Lily that her desire was only a starting point and that she needed life experience to discover what she truly wanted.
• Lily tried the Patronus Charm again, but her Silver Light lasted only five or six seconds; Regulus reassured her and she asked if she could become stronger than him.
• Lily and Regulus left the Abandoned Classroom, and Lily headed for Gryffindor Tower while Regulus returned to the Basement.

Regulus learned that his maternal grandfather, Pollux Black, had died and requested leave from Professor Slughorn to attend the funeral. He left with Slughorn’s condolences and a message for Walburga.

• A Black family owl delivered Orion’s notice that Pollux Black had died and that the family would gather at Grimmauld Place for his funeral.
• Regulus requested leave from his classes, while Sirius received the same notice at the Gryffindor table and silently folded it away.
• Regulus told Professor Slughorn that Pollux had died and asked to attend the funeral.
• Slughorn recalled Pollux’s skill in mediating between families and approved Regulus’s leave.
• Slughorn asked Regulus to give Walburga his regards and tell her Pollux had been an extraordinary man.