Philosopher's Stone

It had taken many days, but finally Kratos, Sesshomaru, Mithos, and friends arrived at Derris-Kharlan. The trip shouldn’t have taken long, but they hadn’t been able to ride the rheiards. Yuan was mad at Kratos and didn’t want to share them with him.
“Please let us use them. This is an emergency,” Kratos tried to explain. “Lloyd, Genis, and the Chosen are all in trouble. We need to get to Iselia and find Raine as soon as possible.”
“Who are those strange people with you?” Yuan asked suspiciously.
“This is Sesshomaru, Jaken, Rin, and Mithos,” Kratos introduced them.
“I knew it! You are still supporting Mithos Yggdrasil and Cruxis!” Yuan yelled. Then he ran off to find more Renegades to help him attack them. They decided this would be a time to leave. Without the rheiards, they had to ride Noishe the whole way to Iselia.
When they finally reached the village, they started looking for Raine.
“Sorry, we haven’t seen Professor Sage in weeks,” the villagers said.
Kratos groaned. “How could we have been so stupid? On the way to the Renegade Base, Raine would have passed the Triet Ruins. She’s probably still examining them!”
Noishe did not like being ridden through the desert and he did not like all the monsters that lurked in the Triet Ruins, so he had hidden in Dirk’s house. So, Mithos, Kratos, Sesshomaru, Sheena, Zelos, Jaken, Rin, Regal, and Presea had to walk all the way back to the Triet Ruins.
Meanwhile…
“Now where do we go?” Tas asked.
“Hurry! Activate the ring! Kratos will kill me if I let a kender in Derris-Kharlan!” Lloyd screamed.
“Okay,” Keyblade said, selecting a random device. A few minutes later, they arrived in a hallway in a large castle.
“Where are we?” Colette asked, looking around in amazement.
“I wonder what’s in here,” Tas muttered as he picked the lock of a large door.
“Stop!” shouted a greasy-haired man wearing black robes. “The headmaster said the third floor corridor on the right hand side is off limits to students! Hmm… You look like Gryffindors, so that will be fifty points each from Gryffindor and detention for you all!” He walked away, smiling unpleasantly.
Bookworm was jumping up and down in excitement. “I know where we are! We’re in Hogwarts! If that corridor’s off limits, we must be in the first book, Harry Potter and the Philosopher’s Stone! Yay!”
“Wait! Slow down! What book did you say we’re in?” Ed asked.
“Harry Potter and the Philosopher’s Stone! It’s one of my favorite books!” Bookworm said happily.
“Why’s that corridor off limits? What does ‘Gryffindor’ mean? Who was that man?” Genis asked.
“That was Professor Severus Snape,” Shade explained, “Gryffindor is one of the four houses of Hogwarts School. Snape hates Gryffindor and takes points from them whenever he can. That corridor is off limits because there’s a giant three-headed dog in there.”
“Why is it in there? I’m sure it would much rather be outside! Poor doggie!” Colette said.
“It’s in there because it has to guard the Philosopher’s Stone,” Shade said.
“Hey! Where did Ed and Al go?” Keyblade asked. They had both vanished. A loud scream came from the room with the three-headed dog.