I did not know going into this that it was a short story. When you are reading ebooks from the library website you can never tell.
This book focuses on the unofficial member of Sigma, Seichan, and her adventures in information gathering. This time it leads her on a quick chase through the catacombs of Paris after a cult.
A very quick read. I wish it was a bit longer so I could get to know her a bit more than the small glimpses I get through other books.
I would say borrow this from the library. Not something that you NEED to own.