Watching Teen Wolf, we didn't get to see much of what really happened in Stiles' head during his struggle with the Nogitsune. We don't know how much of him was actually there while he was void, or what he went through on Mischief Night or when he went missing. This story is the events of Teen Wolf season 3b from Stiles' point of view, with a few added scenes. While it's based off the show, you don't have to have seen it to understand the plot!