|I have given this a thorough read through, as you have requested, and compiled my thoughts for you. I apologise for taking a few days after your request, I wanted to be sure I could be as helpful as possible, so I took more time than usual. I've tried to provide as much feedback as I can. Take it or leave it as you see fit. I hope some of it is helpful to you.
First and foremost, I would like to note that it appears you have labelled your intro as being "non-E". This means that the little blurb about it ("Years of hiding are ruined when Branston is found by his pursuers, and a questionable ally") is not suitable for all audiences. It is! The story may be 13+ (which seems fitting), but the intro is E. If you rate it non-E, it can effect where it is listed around the site and decrease the number of people who see it. As WDC says: "A Non-E rated intro is not suitable for everyone of any age. There may be references to sex, drugs, alcohol, violence, cursing, derogatory names or any combination thereof. These titles are displayed for all members who have their rating preferences set to also include GC and above." The intro rating only applies to the intro. I noticed that you're new to WDC (welcome, btw!), so I thought you might not be aware of this. If you update the intro rating, your work should be seen by more people.
I would like to say that the story is really intriguing to start off with. I see that you have other chapters here on WDC, and I have bookmarked them to be read and reviewed as well, as I'm curious to see where this is going. The story is exciting, easily understood, and leaves just enough obscured to keep me wanting more. It definitely has me interested in the story you want to tell so far. At this point, it definitely seems that the story is the strong point, and it's the technical aspects that need a bit more refining. I enjoy your dialogue, which seems natural, and gives me more insight on the characters I am reading about.
I do have one small detail to nitpick. An arrow, even without an arrowhead, would likely still have punctured skin, especially the shot to the back of the knee. The arrow would be underweight, so it would fly faster. It would also likely not be good for the bow due to the weight difference. An archer who is so apparently talented would (a) know that he would likely do leg damage, possibly long term, and (b) would not want to risk any unnecessary strain on what appears to be the only bow he's carrying. If he had something to throw, that might be more realistically effective without doing permanent/long-lasting damage to Branston's knee. I did see that he felt the pain after, but it didn't prevent him from standing, crouching, or running, and it seems likely that it would.
On to spelling, grammar, and word choice. For the most part, everything you have to say is easily understood, even when there are small errors. You mainly need to work on refining and polishing at this point for chapter one. I have broken down the small errors I noticed into points, that way they can be read a bit more easily.
-In the very beginning you have used the word "clopped." While this is a perfectly fine word, it indicates a certain sound that likely wouldn't be prominent on a snow covered path.
-"His started, he heard the snow behind him crunching, and he let go of his bow to grab the knife that hung from his belt." I think you meant to say "He started" at the beginning of this sentence, but I'm not certain.
-Of the first six paragraphs, four of them start with he/his. It might read a bit more nicely if you played with your sentences to change this up.
-"Branston spoke, careful not to knick his throat on the blade, "Krassos sent you."" The second comma here should be a period, and the proper spelling in this instance is "nick" rather than "knick."
-"The third man yanked off Branston's gloves and his squinty eyes widened. "Yes, sir. This's him."" There should be a comma after "gloves." "Squinty" is perhaps not a good choice of word here, as it's not really a proper word. "His squinted eyes widened" might be a more appropriate word choice here.
-"The man behind Branston slammed into him and fell backwards dragging Branston down with him." This sentence should have a comma before the and.
-The paragraph that starts with "Branston's heard only the wind at first," should be corrected to reflect that "Branston heard" the sound, rather than "Branston's heard."
-"The rider wore a tall steel helmet that hid his face, but he had a crossbow aimed at Faldasir, and he was drawing closer and closer..." Here you've put Faldasir instead of Faldashir.
-In the fourth from last paragraph you've said the horse is "screaching;" the proper spelling here is "screeching."
Overall, this is a really enjoyable story that just needs to go through a more careful editing process a couple times. Don't take this as bad news, it means you have a great start. I've given you a 3.5 star rating, but I'd be happy to come back and give it a higher rating if you let me know when the minor errors have been corrected.