While converting NLM book tag XML to an ePub seems like a relatively straightforward process (hey, an ePub is mostly just HTML, right?), setting up a workflow to do just that is quite challenging. It turns out writing the XSLT could be considered the "easy" part. Other problems, such as dealing with ePub display issues across ebook readers (anything from minor CSS differences to major MathML display problems), deciding what tagging makes the most sense semantically, and figuring out how to give semantic meaning to visual formatting such as table cell shading add a layer of complexity to the process. This paper discusses the challenges, rewards, and as-yet unresolved problems encountered in the process of creating an NLM to ePub3 workflow.