About ten years ago I read most of what I could find of Robert Chambers off of Gutenberg (or wherever), and was surprised at how little it connected to what I knew of the mythos of Lovecraft. My ears perked up when it turned up in True Detective, but apart from the fact that it’s been the two main characters turning themselves inside out, it’s just been a macguffin when it comes to the killer. Perhaps I’m misremembering the Chambers stories.