I dropped the schema and data. I then created three files with just one entry each (Author, Book, and the mapping). I just tried running Bulk Loader with both the --store_xids and xidmap settings on, but am still seeing the same behavior. It creates the Author and Book nodes. Then it creates two empty nodes with just the “authored” edge between them.
Am I off somewhere with quotes?
I’m going to try concatenating the files next to see if that works. If not, then I’ll try switching to RDF format.