https://www.fanfiction.net/read.php?storyid=1582151
and
http://tth.moonlitpaths.com/storyline/story.php?no=2106
Don't know what the link will be for other sites yet.
One of the inspirations for this story was Tara Keezer's story "Stupid Portal", others were Jennifer Oksana's "Real, More or Less" and Roz Kaveney's "Forgiven." I hope that none of the above will feel too insulted...