Hi! I'm here with the review you requested... I hope my suggestions are helpful!!
First of all, the beginning is great. All of the emotions in George's mind are jumbled and confused because he has just lost his twin, and you made his sorrow quite clear. There is, however, a bit of a run-on in the first full paragraph: "When he took a half-step back... Dark space between his fingers." The emotions are good, but I think you could probably break this sentence up a bit. The way I see it, the death of Fred happened so quickly that it needs to be described in terse, choppy bits.
Also, just a style thing: I'm of the mindset that thoughts should be italicized, and if I'm not mistaken, the words you have in parentheses are some of George's sub-thoughts. (He was thinking about something, and then his brain interjected, probably from his subconscious.) Well, that's what I like to call them. The sub-thoughts you have are effective; they're powerful and short, but they would become even more effective if they were italicized. That's just my opinion, though, so don't take it personally if you don't like the idea. :)
I also think that you could have used more "sub-thoughts," especially towards the end. Have you ever read some of Stephen King's novels? He uses those sub-thoughts to really display the character's deepest fears and torments, and I think what you've got here is the perfect sort of opportunity to dig into George's mind.
"I would have forced that last breath back in."--BRILLIANT. This captures perfectly his desperation and longing for his brother. I love it!
There are a few run-ons that could use some trimming. I understand that his thoughts weren't completely coherent when he hit his head, but you could probably cut out a few of the less important words in the sentence "Someone's spell...pinholing my eyeballs."
When George became Fred... Whoa. That whole section was really solid. Change NOTHING!! Because it was perfectly timed and brilliantly executed.
When he held his brother at the end, before Charlie, Bill, and Mr. Weasley tried to pull him away... The imagery there is really nice. I can smell the blood and sweat, and those smells help me visualize the melancholy scene. If you could appeal to the senses (other than sight) perhaps just a bit more throughout the story, it would really tie things together quite well.
The pun was awesome! (Sorry I can't stop saying how awesome this chapter was, but I'm sure you probably don't mind.) For me, though it was intended to be humorous, instead it was ominous. George is cracking under the weight of his sorrow. His defenses are down, he's vulnerable. The pun made that all come up to the surface.
One last suggestion before I wrap this review up: "Laughter. I can hear it still. It is such an odd sound."
To kind of sustain the effect to the end, I suggest leaving "I can hear it still" with the big paragraph and making "Laughter. It is such an odd sound." its own little line at the end. So just a bit of rearranging, but it's also fine the way you wrote it. :)
Thanks for being my first review requester, and I hope that I have not disappointed you!! :)
Author's Response: Disappointed me? NEVER :D
Thank you so much for this much-needed lengthy and very-detailed review! I'm glad you've left a lot of comments on my sentence structures; they are something which are rather inconsistent throughout the story as I have indeed come up with quite a jumble of sentence fragments and run-ons. The first couple of paragraphs had plenty of sentence fragments...but they were rather long fragments, and I do see your point on how the suddenness of the action should be conveyed in "terse choppy bits". I shall most certainly go through this chapter again with all your recommendations in mind.
I'm glad you like parts of the story; I will definitely keep textures in mind while I'm working on descriptive passages.
And I see what you mean about italicising thoughts. I don't read Stephen King but maybe I should just to see how he styles his prose. The parentheses weren't so much deliberate thoughts but...well, moments of umm...consciousness (for lack of a better word). Or echoes, or asides, or strange, rather irrelevant observations. Anyway, I will definitely look at the structure and style of the narrative again!
Well, thank you so very much once again for the wonderful review. Your feedback's been absolutely valuable, and if you don't mind i would like to re-request in your thread.