This story is definitely, without a doubt, AU (alternate universe). Though it will follow the general outcomes of the episodes so far, the adage of a character kind of messes with the whole idea of perfect continuity. That being said, this fanfic is fairly up-to-date as far as the episodes go, and there are certainly spoilers in it for the first season. As I don't know how long it will run for at this time (it's for my amusement rather than actually trying to get anywhere, lol), I can't say exactly what episodes it covers.
Now, with the technical stuff covered: as you may have noticed, I talked about adding a character in. Her name is Heather, and I suppose she could be considered a 'Mary Sue' like character. While I have at least attempted to develop a certain character with her (which is, unfortunately for me, somewhat close to the newly acquired Ana's), there is without question, romantic intrigue between her and Sawyer. This alone, I know, is Mary Sue fodder, since he's the token bad-boy with a past. I tried to handle it responsibly, but hey—this is, once again, for fun. It's not meant to be serious.
One of the main themes so far in this fanfiction is the occurrence of supernatural events, as well as Heather's supernatural experiences. If you're not into the whole paranormal side of the island, then stop here. No really, don't waste your time.
Suggestions are, of course, welcome—but understand that if you totally rip into this (and hey, if you have that kind of time on your hands, feel free) I won't care. Again, this isn't anything serious. It's my own cathartic release exercise. Deal with that as you may.
Rating is for sexual suggestion (which has not developed into anything more so far), as well as frequent cursing.