I read to 'The Hospital Wing'.
Cover: I love this cover, it's complex but not confusing. Nice job! 9.5/10 :)
Blurb: The blurb is pretty basic, but gives a good outline of what to expect. You could add a little more about Bryce, to highlight his importance in the story. :) 7.5/10
Plot and Details: I love stories that run along side the canon (I've written one myself, actually), so that was an instant win with me! However, similarly to my review of 'Long and Lost', I just recommend that you take your time. I have noticed this is something a lot of Movellians (including myself) slip up on some time. Try explain Bryce's relationships with and opinions on each character in turn, for example, when he meets Neville...
'...had a single boy in it. He said his name was Neville.' (I really like the short sentence here, though)
Could be translated to something like...
'After a while of searching, I finally found the only compartment with any room. It was occupied by a single boy. He looked down at his pale hands that rested in his lap, displaying his obvious lack of confidence. His body was far from the peak of fitness and his dark hair was floppy and unkempt. I am immediately saw this boy as someone I could possibly find a friend in, so decided to adopt the seat opposite him. He said his name was Neville. I smiled, a mundane name for a seemingly mundane boy, I suppose.'
Okay, so maybe not like that, but you get my point. The more detail you put into your story the more successful it will be.
Similarly, I had trouble picturing Bryce until you put in the character profiles. It's best if you can get away without these, by using casual hints at his appearance (for example, 'I flicked my head to remove the veil of blonde hair that had gathered over my blue eyes.').
Also, be careful with tense. I noticed the first sentence was present (as I walk, I become, I have), and later changes to past (had, he said, we started). 6/10
Spelling and Grammar: To be honest, your spelling and grammar were pretty good, a few slip ups, but that's to be expected. All I'd say is try to make your sentences longer, as you use a lot of short ones (causing the intentionally short ones to lose effect). 8/10
So, altogether, that's an nine point five, a seven point five, a six and an eight, which gives you a final average of...
Well done! Keep writing and I'll check back soon. :)