First published serially in 1910, The Phantom of the Opera is a Gothic mystery novel about a man who haunts the Paris Opera. Classic elements of Gothic fiction include dark elements, spooky settings, and conflicted characters. Gothic fiction also combines horror and romance. The love triangle between Erik, Christine, and Raoul exemplifies this aspect, especially as Erik manipulates Christine via music.
The opera house is an eerie setting that combines the Gothic elements of isolation and mystery. At times, the opera house seems like the whole world to characters like Erik, who haunts it perpetually, and Christine, who spends most of her time singing. In Chapter 16, Raoul tries to find the underground lake beneath the opera house:
"Excuse me, madame, could you please tell me where to find a gate, a door with bars – iron bars – leading from the Rue Scribe to the lake? The lake! You know, the underground lake beneath the Opera House."
Here, Raoul tries to describe a very strange phenomenon: an underground lake. His insistent repetition of the word "lake" demonstrates his desperation to unlock the mysteries of the building, and by extension, the mystery of the Phantom. Not only is the opera house large and grand, but it also has many secret elements like trapdoors and an underground lake. This lends the story an aura of darkness and mystery that exemplifies the Gothic genre. It also allows Erik to play tricks on people and make them question their sense of reality.
