This is called, The Switch. I'm going to tell you a little bit about it.
When Remilia shoots a fire bolt at Elsa's hand, she accidently changes Elsa's ice powers. Now, Elsa has the power to create summer and wants revenge on Remilia. Now she and Anna are on the run again. With no one they can trust. Except a dog.
Arrow (he's the dog.)
"Can't catch me, Elsa!" Anna cried as she dodged another snowball, Elsa threw at her.
"Oh, really?" Elsa said, creating a giant snowball and aiming it over Anna's snow fort. Anna quickly dodged out of the way just as the snowball hit the ground.
"Hey! Elsa!" Anna laughed. "That was cheating!"
"Really?" Elsa giggled, thowing another snowball. This time, it hit Anna's left braid, causing her streak to return. Elsa noticed it.
"Um..Anna?" Elsa laughed pointing to Anna's braid. Anna looked at her braid and both girls started laughing, unknown that they were being watched by, Remilia.
"I'll just have to find away to get rid of Elsa once and for all, Remilia said to herself. As soon as she spoke those words, she aimed a fire bolt at Elsa's hand and then dissappeared into the darkness. Elsa turned her head around but she didn't see anything. She shrugged her shoulder and tried to aim another snowball at Anna. But instead, she aimed a long vine at her!
"Elsa!" Anna cried. Elsa stared at the vine in complete shock. Anna reappeared next to Elsa and handed her the emergency gloves.
"Remilia..." Elsa said. "Come on, Anna!"
"Elsa, wait!" Anna cried, following Elsa. "Where are we going exactly?"
"To get revenge on Remilia!" Elsa told her sister.
"Do you think we should call the rest of our friends?" Anna asked.
"I think we can manage on our own," Elsa replied. Soon the two sisters started out of Arendelle and through a forset.
"Come on, Anna!" Elsa called over her shoulder. Anna was looking into some bushes, because she heard something. Quickly she followed her sister. Suddenly, Elsa stopped, causing Anna to slam into her.
"What?" Anna asked.
"I think we're being followed," Elsa explained. The girls turned around and saw nothing but a...dog. The dog looked up at Elsa. Reconizing her as the queen, the dog dipped its head and laid back its ears in a bow. Anna reached out her hand to the dog. It quickly jumped in her arms and looked up at Elsa.
"Can she tag along?" Anna asked. The dog trotted up to Elsa and bowed again. Elsa pet the dog on its head and the dog licked her hand.
"Well, I don't see why not!" Elsa said. "Besides, he might come in handy when we need to find Remilia." At Remilia's name, the dog dipped his head and began to see if he could find a trail. The dog folded his ears back and he looked like an arrow.
"How about we call him 'Arrow'?" Anna asked bending down to pet the dog. He reached up and licked Anna's cheek.
"Well..ok," Elsa said. "Come on, Arrow!" Arrow barked happily and followed the two. Anna kept looking over at Elsa and the dog.
"You must've created him, Elsa," Anna pointed out.
"Maybe..." Elsa said looking down at her hands, which had the emergency gloves on over them. "Once we find Remilia, I'll turn him into a snow dog, so Olaf can have a friend." Arrow pricked his ears and started growling.
"He must've found her scent!" Elsa exclaimed. "Come on!" The trio quickened their pase and followed their dog.
(Part 2 coming soon!)