CHAMBER OF SECRETS VS. PHANTOM OF THE OPERA

 Chamber of Secrets has a lot in common with Phantom of the Opera:

1. The villain's lair is deep under ground and contains a lot of water
2. The villain has an unassuming first name (the Phantom=Érik, Voldemort/Riddle=Tom)
   
3. The villain conceals his identity (Érik behind a mask and the mirrors, Tom Riddle behind his youthful appearance and his diary)
   
4. The villain communicates with the innocent, bullied outsider heroine (Christine/Ginny) without revealing his face (Érik through the mirror, Riddle through his diary). He gains her trust until she trusts him completely
   
5. The villain takes the heroine into his underground, watery lair
6. The heroine is saved by her love interest, a young idealist and (in Harry's case, future) agent of law and order: Raoul the military officer/Harry the future Auror (wizarding military/police)

Quantum Harry reiterates the Red Riding Hood parallels (redheaded innocent Ginny=RRH, Riddle/Basilisk=Big Bad Wolf, heroic Harry=Huntsman), but I can't unsee the PotO parallels that are far clearer.

Given that Rowling has majored in French and has French ancestry herself (Fleur Delacour=flower of the court, Bellatrix Lestrange=strange warrior [Lestrange is a real Anglo-Norman surname], Draco Malfoy=dragon of ill faith - besides the pale and platinum-blond Malfoys and their neoclassical estate bring to mind the Bourbons of the eighteenth century - and, the icing on the cake, Ron and Hermione call their son Hugo Granger-Weasley - a Victor Hugo reference? Harry's childhood with the Dursleys calls to mind both Cosette and Cinderella [and Dudley reforms just like Éponine!], Lupin concealing himself as a werewolf calls to mind both Triboulet [Rigoletto] and Quasimodo - plus the Lupin surname, not only as Canis lupus but also as Arsène Lupin!), I think all the Phantom echoes in Chamber were intentional on Rowling's part! Chamber is a whole-plot reference to Phantom set in Hogwarts...