Otherwise known by its French title,
Notre Dame de Paris. I don't know why they changed it, considering that Victor Hugo pretty much stated that the Notre Dame cathedral was the main character, but I digress.
The story is about the interactions between these characters:
-Gringoire, a struggling playwright
-Frollo, a priest
-Esmeralda, who makes her living as a dancer and does tricks with her pet goat, Djali
-Quasimodo, who is Frollo's adopted son and is the bell-ringer for Notre Dame
-Phoebus, a soldier
There's also other characters, like Jehan, Frollo's brother, Fleur-de-Lys, who is betrothed to Phoebus, Gudule, a recluse who still grieves over her lost daughter, and Clopin, king of the Truands.
To make a long story short, one night, Gringoire follows Esmeralda and watches her get kidnapped. She is saved by Phoebus and falls in love with him. Frollo, who along with Quasimodo, was doing the kidnapping, as he became obsessed with Esmeralda. She ends up marrying Gringoire in order to save his life (long story), but the relationship is more or less platonic. Esmeralda and Phoebus meet up one night, but a jealous Frollo stabs him and she is framed for the murder. Nice.
It's a very good book and I'm trying not to spoil it for everyone who hasn't read it. There was a Disney version that came out, I want to say 1997, and I think it's pretty good. However, this thread's about the original novel, so fire away. :)