Exert from a Book

I started this book called "Melody's Song" a while ago and now am picking it up again to fix it and complete it. Here's one of my favorite parts:

"AHHHHHHHHHHHHH! HELP!"
"Gus!" They all stood up quickly, Melody the first to run towards the direction of the screams. It was so difficult to run through the briers and the trees and the screaming continued, echoing in her ears, telling her to run faster. She took off her body in pain her insides wanted to burst open, then it was over, she was in the air, flying as fast as her wings could carry her. Her crow eyes could see better in the dark, and soon she had caught up with the screams.

Gus was backed up against a tree, fighting off a giant black dog with a pathetic looking stick. Melody landed, quickly changed back to her humans form and drew her sword as she swiftly approached the creature, but the beast was too quick for her and before she could attack it bit down hard on her leg with razor sharp teeth that crushed upon her bones. She stabbed the beast in the left eye with her sword, as Gus came down upon its head with his stick from behind. The creature released Melody, who fell upon her stomach, unable to walk. Then, it turned on Gus again and leaped upon his chest. Gus screamed in pain, as Melody desperately tried to get up, staring at the creature... her blood still glistening on its teeth. It stared at her for a moment, then ripped its claws into Gus's chest, blood splattering all around, and a line of it hit her face. She cried out weakly for help, though sure her voice did not carry and watched helplessly as the monster bit through her friend's flesh, the sound of crushing bones filling the silence of the night. Gus wasn't moving anymore and the creature was consuming his flesh and to Melody's horror, his heart. Gus lay dead and the large dog turned towards Melody, blood dripping from his mouth and meshed all over its fur.

"Oh God... please don't eat me... don't eat me..." she gasped as she tried to stand again and in failing attempted to crawl away from the creature, but it grabbed her ankle with its teeth and began to drag her away. She screamed in agony, her leg numb with intense pain.

"Go back from which you came, creature of the shadows," Quinn's booming voice came from behind her and before her eyes the great black dog faded from view, first becoming see through then disappearing entirely.
"Melody," Tom ran to her side, "are you okay?"

"He's dead... that thing... it killed him..." she said weakly.

"Tom, help her walk, Coby, picked up Gus. He is not dead... though technically he is not alive.. That creature that ate his heart..."

As Tom helped Melody off the ground he stared at Quinn and said, "What?"