Recaps

Douglas trained Hogwarts students through dangerous practical lessons while helping Sirius and Lupin and preparing to uncover the truth about Scabbers. After Dementors disrupted a Quidditch match, Harry learned about the Marauder's Map and spent his money trying to win it through George and Fred's prize draw.

• Douglas encouraged academic competition, advised Hermione on using her Time-Turner, and helped launch the Charon Detective Agency, where Draco hired the students to investigate Sirius Black's case.
• Douglas developed Wolfsbane potions with Lupin, tested a Homorphus Charm during Lupin's transformation, and trained younger students on a hazardous obstacle course.
• Harry suspected Sirius was a werewolf, but the students found weaknesses in the case against him, and Douglas kept the investigation moving while protecting Scabbers in an enchanted cage.
• Lavender's rabbit died, prompting discussion of Trelawney's predictions, while Douglas explained that her genuine prophecies were rare.
• Dementors invaded during a Quidditch match, but Harry's crane Patronus and the students' defensive magic drove them away, and Douglas questioned Fudge and Umbridge about the breach.
• After George and Fred heard that Douglas's dog was called Padfoot, they gave Harry the Marauder's Map and revealed its prize-draw ritual.
• Harry spent his Galleons on repeated draws, ran out before completing the map, and went to Douglas's office for money, where Sirius stopped Wangcai from reclaiming Dobby's pouch.

Harry and his friends followed the Marauder’s Map and other clues to uncover that Scabbers was Peter Pettigrew, while Douglas and the professors managed the investigation around them. Peter confessed to betraying the Potters but escaped Hogwarts, and the Ministry withdrew Sirius Black’s warrant and issued one for Peter.

• Harry lost forty-eight Galleons trying to draw the final Purple Map Fragment, then learned from George and Fred that refusing to keep playing would have earned him the Marauder’s Map.
• Harry found Peter Pettigrew’s name on the map, and he, George, and Fred discovered that Scabbers’s cage made the dot overlap with theirs.
• Harry, Ron, and Hermione investigated Scabbers and the Marauders, while Douglas and the professors dealt with exams, Hogwarts disturbances, and Ministry official Umbridge’s W.O.M.B.A.T. test.
• After the Charon Detective Agency found traces of Peter, Douglas revealed to Ministry officials that Scabbers was Peter Pettigrew and the students gathered to open his cage.
• Percy opened the cage, and Fred and George woke Scabbers, who transformed into Peter and denied betraying the Potters.
• Peter accused Lupin and Sirius, but Hermione’s questions and Sirius’s arrival exposed his contradictions, and Dumbledore confirmed that Peter had leaked information to the Death Eaters.
• Peter admitted that fear and resentment had led him to betray James and Lily, then changed into a rat and escaped after the students and Aurors tried to stop him.
• Douglas paid Fudge fifty thousand Galleons to withdraw Sirius’s warrant and issue one for Peter, then used Pet Food and his Magic Radar to track Peter still inside Hogwarts.

After Sirius was cleared, Harry reunited with him and visited Godric's Hollow, where he resolved to restore the Potter home and named Sirius its Secret Keeper. At Grimmauld Place, Douglas uncovered Regulus's story and Slytherin's Locket, then led the group to Voldemort's cave, where they subdued the Inferi and found the island at the lake's center.

• Douglas revealed to Harry that Sirius had been the dog Harry knew as Padfoot, and Harry reunited with Sirius and received his gift.
• Sirius and Lupin took Harry to Godric's Hollow, where Harry saw the memorial and his parents' grave, then recognized the ruins of his former home.
• Harry decided to restore the Potter home, named Sirius its Secret Keeper, and watched Sirius place the Fidelius Charm over it.
• At Grimmauld Place, Douglas questioned Kreacher about Regulus and learned that he had taken Voldemort's locket from the cave.
• Kreacher recounted Regulus's sacrifice, and Douglas identified the locket as a Horcrux and sealed it in an Anti-Magic Stone Box.
• Douglas, Dumbledore, Sirius, Lupin, and Kreacher entered Voldemort's cave to recover Regulus's remains, and Douglas altered the ward protecting its concealed entrance.
• Douglas used a speedboat to draw the Inferi together, while Dobby trapped them and the group attacked before Douglas's Soul-Subduing Stele suppressed them.
• The group saw a stone slab and basin on an island at the lake's center.

Douglas and the Hogwarts professors memorialized Regulus and built a hidden training realm while Voldemort returned to a new body with Wormtail’s help. The story left the students on their London outing, learning about Muggle education and technology and considering its impact on the magical world.

• Douglas and Dumbledore discovered that Regulus had bypassed the island’s defenses with house-elf magic, and Sirius recovered his brother’s body from the lake.
• Douglas sealed Regulus’s remains in the cavern, where he, Sirius, Lupin, and Dumbledore protected the tomb and honored Regulus with a bust.
• Percy and Penelope led seventh-year students into the Chamber of Secrets for Moaning Myrtle’s seven-part challenge, while Neville later defeated Draco’s giant snake and founded the Swiftwind Sword Club.
• Douglas took Dumbledore and the Heads of House through the Demon-Suppression Tower and showed them Voldemort’s treasure cave, its traps, and the hidden entrance to the training realm.
• The professors honored fallen fighters against Voldemort and helped Douglas modify the entrance into a challenge guarded by a statue modeled on young Voldemort.
• In Albania, Wormtail found Nagini and helped Voldemort return in a shriveled new body, then endured Voldemort’s curses and orders as they prepared to leave the cave.
• Douglas brought Hogwarts students to London, where they visited University College London, saw Muggle recording technology, and discussed how electricity and technological progress could affect magic.
• Douglas showed the students a documentary about Muggle history and assigned them to compare it with magical history, leaving Percy troubled by the implications.