The Elder's Circle, Book II of The Elemental Chronicles

Picking up right where Gateways, Book I of The Elemental Chronicles left off, Victoria's wish to go home is interrupted. The dreamwalker proves to be a powerful tool, but Victoria doesn't know how to control it, and wakes up in different terraces surrounded by people of different cultures; not all of whom welcome a mage of her abilities.

Separated from her mentors, Victoria's journey is fraught with danger:

"No!" Victoria yelled. Raising her hands, she drew the Air to her and welcomed its eagerness to help. In the back of her mind, where her mediation garden had been stripped, she saw dark storm clouds rolling in and felt the twisting surge of lightning's willingness to enter her world with burning fingers.
James backed up but his guards kept their grip on the brothers.
"Let them go," Victoria said.
"Or you'll call lightning?" James said.
"I don't have to call it," Victoria said. "It's already here." A white-hot bolt struck outside and all the guards jumped. The one holding Tucker let go, but Bobby's capturer was too stubborn. Victoria tipped her head and looked at him. "Really?" she taunted him. "You think your element is a match for lighting?"
James laughed, but signaled to the guard holding Bobby to let him go.
Bobby straightened his shirt and walked over to Victoria.
Tucker shook his head at Bobby. "Dude. We were just rescued by a girl."
"Now what?" James asked. "You think you can take us all on?"
"I don't want to fight," Victoria kept her hands up and encouraged a strong breeze to sweep through the windows. "But, yeah, I think I can take you all on."
She felt Bobby tense at the idea, but she could see Tucker smiling at her courage.
James believed her. He had seen it. Milo had not. Without warning, Milo charged forward, his earth element shaking the floor. Victoria encapsulated him in a bubble of Air where he remained suspended inches off the floor with a look of embarrassed anger on his face. Reggie loosened the ground under Victoria's feet, obviously hoping to knock her over and weaken her hold on Milo. Keeping one hand toward Milo, she reached her right hand out and halted the cracking ground.
Reggie gasped. "Two elements."
"You are the one." James smiled. "Ona was right."
"Ona was NOT right! She used me and threatened my friends." Dark, foggy anger slipped into her mind. Light flashed in her mind and she winced at the stinging heat of it. Everyone took a step back, even Bobby and Tucker. That's when she saw it. The lightning in her mind wasn't just a weapon. When it ripped across the sky in her meditation garden, she caught a glimpse of a different place.