I'm not sure specifically as it could be a very unique fan - made story. It might involve a character named Draco being held hostage near a lake in the context of a fictional world created by the fanfic writer.
Well, first, check the major fan - fiction platforms. Archive of Our Own is known for having a vast collection of fan fictions. Another option is Wattpad, although it has a broader range of content. Search for the title 'draco is a lake hostage fan fiction' on these sites. Also, some fandom - specific forums might have links or discussions about this particular fanfic, so it's worth looking into those as well.
One common theme could be rescue. Since Draco is a hostage, there might be a focus on who will rescue him and how. Another theme could be his inner struggle while being held hostage. He might be dealing with fear, helplessness, or trying to find a way to escape on his own.
I'm not sure specifically as I haven't read this particular fan fiction. But generally, it might involve a rescue mission to save George from the hostage situation in or near the lake, with some romantic elements intertwined, like a character having romantic feelings for George and being the one to bravely attempt the rescue.
I'm not sure specifically which 'draco is a lake hostage' fanfictions are good. You could try searching on popular fanfiction websites like Archive of Our Own. There might be a variety of works there with different takes on this concept.
Perhaps it's a new dark creature that has emerged in the Black Lake. This creature sees Harry as an easy target and takes him hostage, either for food or for some other unknown reason. It could be that this creature has some sort of grudge against humans or wizards in particular.
Since I haven't read it, it's hard to say for sure. But it could be a friend or a love interest. Maybe a person named Mary who has a crush on George and will do anything to save him from the hostage situation at the lake.
Well, one possible plot twist could be that Harry discovers he has a hidden power that allows him to communicate with the creatures in the Black Lake. This power could help him either escape or turn the situation around against his captors.
I'm not sure of specific 'fenris hostage fan fiction' works off the top of my head. But you could try searching on fan fiction websites like Archive of Our Own. They have a large collection of fan - made stories and might have some related to this topic.