I've been writing fanfic in my head for over 30 years – which just shows how very old I am! This is the first time I've ever put a story down on paper though, so please be merciful.
I wanted to explore how the Weasley family, particularly George, found out about Fred's death – how they got from the point where Percy and Harry hide his body to the point where they are all around him in the Great Hall, and what happens afterwards, especially when Charlie arrives. I didn't actually intend for George to find out in the way he does, but that was how it turned out. Nor did I start out meaning the whole thing to be from Bill's POV, but again, that's how it happened – and I do like Bill!
More to follow when I type it up.
(Disclaimer: Harry Potter and the Weasleys aren't mine. I wish they were.)
I've just re-read the book and had to re-write a bit since Bill and Percy shouldn't have been in the same place as the twins at the start of the battle... I think this works okay!
The four Weasley brothers were fighting together. Bill and Percy had been with the Hogwarts defenders in the grounds, but had been driven inside as the Death Eaters relentless advance continued. By the Grand Staircase, they had come together with their twin brothers, who had relinquished their posts by the secret passageways when it had become obvious that the Castle's defences were breached. Sometimes side by side, sometimes back to back, the four brothers battled the advancing Death Eaters. Fred and George were clearly enjoying themselves – even as Fred blocked a curse that would have felled his twin, they were grinning, revelling in the fight and their chance to play a part in Voldemort's downfall. The tiny part of Bill's mind he could spare from fighting wondered if those two would ever take anything seriously. Percy was beside him, fighting more recklessly than even the twins, obviously delighting in being with his family again and longing to prove where his loyalties now lay – where they had probably always lain if his pride and ambition would have let him admit it earlier.
Bill wished he knew where the rest of the family were. It felt safe somehow to be fighting so closely with three of his brothers; he just wished the others were there too. He had not seen Fleur or his parents since the battle began. Another small part of Bill's brain was keeping up a silent refrain: "Let Fleur be okay, please let her be okay." Ron was off somewhere with Harry and Hermione of course; and Ginny, he devoutly hoped, was safe in the Room of Requirement as her parents had insisted. Charlie hadn't made it back yet – though Bill had a sneaking suspicion that the brother he was closest to would turn up before this was all over.
"George, Bill, watch your backs!" Fred's shout came just in time. Bill and George whirled, and their simultaneous spells felled the Death Eater who had been advancing behind them. But there were others with him, and Bill and George were separated from their brothers as they fought their way clear. Fred and Percy, meanwhile, were slowly and remorselessly being driven into a side corridor by the two hooded figures in front of them. The last Bill saw of them as the fight drove the two pairs of brothers apart, was Percy flinging spell after spell at their attackers, while Fred grinned and mouthed : "See you later, have fun" at him and George.