Book I Summary

Chapter 1: The Great Hall of the Palace of Justice

A crowd waits for a morality play to begin at the Palace of Justice in Paris on January 6th, 1482.
Today is the Epiphany, and the people are celebrating the Festival of Fools.
Some students, including Joannes Frollo de Molendino (sometimes he goes by Jehan du Moulin, or any variation of those words), are being loud and rowdy. You can tell who the students are because they occasionally shout things in Latin.

The crowd gets restless for the play to begin, but they're supposed to wait for some VIPs to make an appearance: namely, the Cardinal de Bourbon, some Flemish ambassadors, and Margaret of Flanders (who is betrothed to the Dauphin—that's the guy who is going to inherit the French throne).
A man in black tells the actors to begin. As he tries to impress the ladies in the front row, we find out that he's Pierre Gringoire, the play's author, and that he has quite a high opinion of himself.
During the play (which isn't nearly as good as Gringoire thinks it is), a beggar climbs up onto the balustrade to beg for alms. Joannes Frollo recognizes him as Clopin Trouillefou, and he causes a ruckus.
Gringoire is ticked off that no one is paying attention to his play.
The plot of the play is that four allegorical figures—Labor, Clergy, Nobility, and Trade—are travelling to bestow a gold dolphin on the prettiest woman in the world. The play is a heavy-handed metaphor about the Dauphin's betrothal to Margaret of Flanders. The Dauphin is the dolphin. Get it? Har har.

Just then, who should arrive fashionably late and with some loud fanfare but the Cardinal de Bourbon, along with his retinue of kind-of-important people. This pretty much ends all audience interest in the play.

One man named Jacques Coppenole insists on being announced with the others. When asked his title, it turns out that he's just a hosier (literally, someone who makes hose, or medieval pants).
The audience loves this, and Coppenole becomes their favorite—more so than the Cardinal, who's not too happy about it.
Coppenole recognizes Clopin Trouillefou and loudly announces it. The Cardinal starts to find the Flemish to be a rowdy bunch.
Gringoire is still trying to salvage his play, which no one has been paying attention to for a while now.
Finally Coppenole gets thoroughly tired of the play and suggests that the audience find the ugliest grimace among them and crown a Pope of Fools. The crowd, also bored with the play, is totally down with this idea.

The audience breaks a rose window. People stick their heads through it and make faces. It's a pretty ugly sight—or rather, several ugly sights.
One guy, though, takes the cake. He has a huge nose, a small eye, a wart obscuring his other eye, red hair that sticks out, and a tooth that juts out. This dude totally gets elected Pope of Fools.
The crowd goes wild, but then they go even wilder when they realize that the dude's grimace is actually his normal face.
Someone recognizes this dude as Quasimodo, the bell-ringer of Notre-Dame. We learn that Quasimodo is deaf from ringing those enormous bells.

As the crowd empties out to celebrate their new Pope, Gringoire still holds out hope for his play.
One of Gringoire's students shouts that La Esmeralda is in the square, and the few remaining people run to the windows to see.
So much for the play.