Isabelle overheard the entire thing. The only few times she ever saw him get that angry was when he found out that she was seeing that gypsy boy. He banned her from going to the cathedral for a while after that, and made sure that someone was watching her the whole entire time she was there from then on.
After he was entirely gone, Isabelle came out of her hiding place at the same time as Phoebus.
"We have to find the Court of Miracles, before daybreak. If Frollo gets there first...are you both coming with me?" Phoebus said, as he emerged from under the table.
"We can't," they both replied sadly.
"I thought you were Esmeralda's friends," Phoebus scolded them.
"Frollo's my master. I can't disobey him again," Quasimodo said.
"She stood up for you. You've got a funny way of showing it," Phoebus replied.
"It's not that we don't want to, we do, very badly, but we just can't get caught again, especially me. The last thing I need is to be locked up in that dungeon again. Just thought of it terrifies me," Isabelle remarked.
"Wait, did Frollo-"
"Yes, he raised me too, except in the Palace of Justice," Isabelle interrupted Phoebus.
"Ah. Well I'm not going to sit by and watch Frollo massacre innocent people. You both do what you think is right," he said as he turned and left.
Quasimodo then turned to Isabelle.
"What are we supposed to do? Go out there and rescue the girl from the jaws of death, and the whole town will think I'm some kind of hero? She already has her knight and shining armor. Frollo was right. Frollo was right about everything. I'm tired of trying to be something I'm not," he told her.
Isabelle started to think.
"You know what? I don't care. I don't care if Frollo catches us or not, he doesn't scare me anymore. I'm going out there and helping Esmeralda if it's the last thing I do. Come on, Quasi!," called out as she tired to catch to Phoebus.
Quasimodo stared and Isabelle for a second.
"I must be out of my mind!" he exclaimed to himself as grabbed his cloak and also caught up with them.
Isabelle ran to ground level until she finally caught up with Phoebus.
"Changed your mind?" he said happily to her.
"Yeah," she answered back, catching her breath. They then made their way towards the exit.
"Phoebus!" he cried out, right when he was exiting the cathedral. Both Phoebus and Isabelle jumped in surprise. "Sh! I'm coming with you."
"I'm glad you changed your mind too," he said to Quasimodo.
"I'm not doing this for you, I'm doing it for her," Quasimodo responded.
"Do you know where she is?" he asked curiously.
"No, but she said this would help us find her." He pulls out a talisman and handed it to Phoebus.
"Good, good, good. Ahhh. Great! What is it?" he asked.
"It's a talisman," replied Isabelle. "It looks like has some kind of map on it." She was examining it.
"Map? Of what? Looks more like some sort of code. Maybe it's Arabic. No, no. It's not Arabic. Maybe it's ancient Greek..." guessed Phoebus.
"When you wear this woven band, you hold the city in your hand," Quasimodo whispered to himself.
"It's a map, I'm telling you," Isabelle told Phoebus. "See? This is the cathedral, the river, and that is the graveyard-" Phoebus interrupted her.
"But I've never seen a map that looks like this and..." They all stop talking at the same time.
"...and this is it! exclaimed Quasimodo. Isabelle is right!"
"...and this is not it!" argued Phoebus. Both men breathe in deeply and Phoebus gives in.
"All right, okay. You say it's a map, fine, it's a map. If we're going to find Esmeralda, we're going to have to work together. Truce?" he said as he slapped Quasimodo on the back.
"Well...okay," he said as he slapped Phoebus on the back, as he winced in pain. "Sorry," Quasimodo added as he walked off.
"No you're not," said Phoebus as Isabelle chuckled.
They then walked to the graveyard, not far from the cathedral. They reached an iron gate and opened it. They soon reached the same symbol that was on the map.
"This looks like the symbol on the map," said Isabelle.
"But what does it mean?" inquired Quasimodo.
"I can make out the inscription, but it's going to take a few seconds to translate it," replied Isabelle.
Just then Quasimodo pushed the lid off of the grave, revealing a secret staircase going down.
"Yes, well, we could just go down those stairs," Phoebus then said.
They went down the stairs and it took them to a flooded chamber, lined with skeletons.
"Is this is the Court of Miracles?" Quasimodo asked.
"Offhand, I'd say it's the Court of Ankle Deep Sewage. Must be old catacombs," Phoebus replied.
The three of them proceeded to to walk in it.
"Cheerful place. Makes you wish you both got out more often, eh?" Phoebus remarked.
"Quite," replied Isabelle.
"Not me. I'm just here to warn Esmeralda and get back to the bell tower. I don't want to get in any more trouble," Quasimodo said adamantly.
"Speaking of trouble, we should had ran into some by now," replied Phoebus.
"What do you mean?" asked Quasimodo.
"You know, a guard, booby trap..." Suddenly the light on the torch was blown out.
"...or an ambush," finished Isabelle.
The chamber is suddenly fully lit and and they're surrounded by skeletons. They forced the three on their knees in front of a unmasked Clopin.
"Well, well, well. What have we here?" he asked.
"Trespassers! Spies!" the skeletons cried out.
"We are not spies!" cried out Phoebus.
"Can't you listen-" both Quasimodo and Phoebus were gagged. Only Isabelle was not.
"Ah, and you must be Isabelle! Esmeralda told me you were coming here! You there!" Clopin cried out to one of the skeletons. "Take her to see Esmeralda!" he said pointing at her.
But before she could say anything, one of the skeletons walked over and led her away down the tunnel. When she finally was able to talk, she said,
"They're not spies, they're with me!" she tried to tell him, but he completely ignored her.
Soon they reached a large colorful room with wagons and such. It was the Court of Miracles! Isabelle just stared in awe, thinking this what Frollo has been after all this time. She couldn't believe she was in it. The man in the skeleton costume then led her to a tent, called out for Esmeralda. As soon as she and Djali came out, she gave Isabelle a huge hug.
"No time to explain, they're going to hang Quasimodo and Phoebus! They think they're spies!" Isabelle exclaimed to Esmeralda.
"Follow me!" she said leading Isabelle towards the platform where, they were about to hang them.
Right when Clopin was pulling the lever to hang them, Esmeralda called out,
"Stop!" as she made her way towards the platform with Isabelle walking behind her.
"Esmeralda!" both Phoebus and Quasimodo cried out under the gags over their mouths.
"These men aren't spies-they're our friends!"
"Then why didn't you say so?" asked Clopin.
"We did say so!" both men replied irritated as Esmeralda untied them.
"This is the soldier who saved the miller's family," pointing to Phoebus, and Quasimodo helped me escape the cathedral," she said pointed to Quasimodo.
Phoebus began to shout to the crowd,
"We came to warn you! Frollo's coming! He says he knows where you're hiding, and he's attacking with a thousand men!" Esmeralda joined in.
"Then let's waste no time! We must leave immediately!"
All of the gypsies begin running around and packing up their things, preparing to leave.
Esmeralda turned to Phoebus.
"You took a terrible risk coming here. It may not exactly show, but we're grateful," she told him thankfully as she gave him a hug.
He looked over at Quasimodo and Isabelle who were just getting down from the platform.
"Don't thank me, thank them. Without their help, I would have never found my way here," he said.
Then suddenly another old too familiar voice was heard from the distance.
"Nor would I!" It was Frollo.
His soldiers swarm around the place taking gypsies, surrounding them and took them into custody along with Quasimodo, Isabelle, Esmeralda, and Phoebus.
"After twenty years of searching, the Court of Miracles if mine at last!" He turned to Quasimodo. "Dear Quasimodo, I always knew that you would be someday of use to me," he said as he stroked his hair and humped back.
"No," Quasimodo said in despair.
"What are you talking about?" asked Esmeralda to Frollo being restrained by a guard.
"Why, he led me right to you, my dear," he replied, caressing her cheek.
"You're a liar!" she replied in anger.
"And look what else I caught in my net-Captain Phoebus, back from the dead. Another miracle, no doubt. I shall remedy that." He then walked to Isabelle with a wicked smile. "My dearest, Isabelle," he said, stroking her hair and cheek. "I see you have ventured up into the bell tower and met Quasimodo, but soon, you shall never see him again nor ever see the light of day," he chuckled wickedly.
"Father no! You can't do that! I love him!" Isabelle cried out loud. She immediately stopped pulling on the guard, retraining her abruptly in shock that she said that out loud.
Quasimodo looked over from the circle of guards that he was in and showed her one of the biggest smiles he's ever had on his face. She loved him back, after all!
Frollo's wicked grin turned into an evil glare upon hearing this and seeing Quasimodo's reaction. He then said to the crowd,
"There will be a little bonfire in the square tomorrow and you're all invited to attend!"
"No, please, master!" begged Quasimodo as he grabbed on to the bottom of Frollo's robe." Frollo looks back and glares at him. "No, no," Quasimodo said in despair as Frollo walked away. He ordered his guards,
"Take him back to the bell tower. And make sure he stays there." He then walked towards Isabelle and gripped her upper arm, hard. She winced in pain. "You are coming with me personally, my dear," he said as he dragged her with him.
All she could do was look back at Quasimodo who was not even moving, guards literally dragging him on the ground, by his arms. She wasn't even thinking about what was going to happen to her exactly anymore.