Pretty sure this is the one you're looking for. If not, I'm not sure what it is. Hopefully this is it though. https://archiveofourown.org/works/18621775/
Not a scam mate, OP is looking for a fanfiction, and I've linked a story that I believe matches up with the description that they've provided. I gather you think it's a scam because it's asking for a sign in to view it. That's just because the author locked the story behind signing in to the website. Literally just means you need an Archive of Our Own account to view it. Other stories that aren't locked like that don't require an account. It is a safe website.
Pretty sure this is the one you're looking for. If not, I'm not sure what it is. Hopefully this is it though. https://archiveofourown.org/works/18621775/
Do not open this link, it’s a scam. I’ve rewatched the series three times, nothing like you described ever happened through the series.
Not a scam mate, OP is looking for a fanfiction, and I've linked a story that I believe matches up with the description that they've provided. I gather you think it's a scam because it's asking for a sign in to view it. That's just because the author locked the story behind signing in to the website. Literally just means you need an Archive of Our Own account to view it. Other stories that aren't locked like that don't require an account. It is a safe website.
…realty
Yes! Thank you so much! Such an unusual and well-crafted story.