Ourboros is a tight novella that has its foot in Asian folklore in one moment, and American hitman-noir at the other. A mysterious hitman named "O" remains at the center. He's cruelly effective, partly because he's a host to a dragon-god. Of course, as noir typically goes, "O" takes on a job that turns out a little more than what it seems. However, while that aspect of the plot construction has been done before, it's a staple of the genre. Koehler excels at making it her own, which makes Ouroboros quite a unique read.