Fred looked up just in time to see the dark witch pointing her wand at him. "Avada Kedavra!" Fred narrowly missed the curse she sent at him. In the past few hours, he had defeated a great number of the Dark Lord's followers, too many than he'd care to count, and yet this one witch has proven to be a greater foe than he originally believed her to be. He still had yet to send a curse at her that she didn't deflect with ease.
His thoughts briefly went towards his twin, who he had lost track of some while back when they were separated by a small explosion. He wished that George were here with him, both so he would have someone to watch his back, and so he would be able to know that his twin was alright.
Gathering up his strength, he aimed his wand at the witch with what he hoped would be a successful curse, but was suddenly distracted by a faint hissing in the breeze.
You have fought valiantly, Fred heard a snake-like voice whisper. But in vain. I do not wish this. Any drop of magical blood spilt is a terrible waste.
Fred had never heard a voice filled with so much hatred and evil before. What could cause a creature to be filled with such hatred? Fred absentmindedly kept his wand aimed at the dark witch, but didn't think her much of a threat, considering that she was also intently listening to the whispering voice.
I therefore command my forces to retreat. His forces? Could the voice be-? No. It couldn't be Voldemort. But then, who else could it be?
In their absence, dispose of your dead with dignity.
Not wishing to spend any unneeded time away from George, Fred started running towards the last place that he saw his brother. He hoped that his twin was alright, and that no harm had come to him. Fred considered himself rather lucky that he hadn't sported any serious injuries. That is, until he was thrown against a wall by a large explosion, and his vision went black.
George had been searching through the cast for almost an hour and still had not managed to locate his twin. He hadn't remembered the exact moment when they were separated, so he had nothing to go on. He figured that he would just be able to tell where Fred was, but unfortunately that didn't really work out. So he had resorted to blindly searching through the castle.
"Fred? Where'd you get off to?" George started to feel anxious. The Weasley twins had never been separated for as long a time as this. It made George feel incomplete, in a way. Fred was there for everything George went through, as George had been there for Fred. Even with the whole war going on, George never felt as horrid as he did now; he knew that no matter what happened, as long as Fred was there, they would get through it. "Come on, Fred. Where are you?"
George turned corner after corner, going upstairs and downstairs, through the dungeons and on the roof, but he still hadn't found his brother. Where could he have gone off to?
Finally, George neared the end of a long corridor. He hadn't been in this part of the castle yet, so he had no idea what to expect once he turned the corner. But even in his wildest dreams George would not have expected this.
"Fred?" the red-haired boy said, hoping that this was not in fact his twin. He ran as fast as he could and skidded to a stop next to the all too familiar boy. He put his hand on Fred's chest and thanked the stars that he felt it rise and fall, albeit weakly.
"G-Georgie?" the wounded boy asked shakily, coughing from the exertion.
"Hey. Hey Freddie," George said, sighing in relief from hearing his brothers voice. He pulled the wounded boy onto his chest and began absentmindedly carding his hands through his brothers red hair. "How are you feeling?"
"Bloody brilliant, thanks for asking," Fred croaked, cracking a half smile. Although this smile was broken as the young boy went into a fit of coughing. George tightened his grip on his brother and muttered soothing words, hoping that it would calm his brothers coughing. Once his fit finally stopped, Fred whispered, "George?"
"Yeah?"
"You hurt, George?"
"No," he replied. "No, I'm fine, Freddie."
Fred smiled relaxed slightly. "Tha's good," he mumbled, his breathing growing weaker.
"Hey, come on now. Don't do this Freddie," George said, sensing his brother beginning to fade. "Just breathe Freddie. Please. For me?"
"'m tryin'," Fred said, but he was loosing his grip on consciousness. Slowly, he closed his eyes, and the world around him faded to black.
"No, no, no, no, no. Come on, Fred. W-wake up!" George put his shaking hand on his brother's cold face. "Y-you can't be dead. Please, Fred! You pr-promised you'd make it out alive! Don't you dare leave me now."
George looked into his brother's lifeless eyes, hoping, pleading, for some response. But none came.
"Come on, Fred!" George desperately shook his brother, hoping to wake him up. Finally, the boy realized that nothing could bring his brother back, and he sobbed into Fred's bloodstained shirt, hoping that this was all just a bad dream.
George sat there for nearly an hour, his sobs gradually dying down to only the occasional cry of distress. This is when Arthur and Molly found him. Arthur, saddened beyond belief but keeping up a front, knelt down and picked up Fred so they could take him to the hospital wing and to the rest of their family. Molly let out a cry herself when she saw that her two boys had been reduced to one. She ran over to George, holding her boy and comforting him while she herself couldn't hold back the tears.