The premise of this novel caught my eye, essentially combative nuns training others to kill. I'm not a fan of religion so I was hesitant going into the novel, however, LaFevers keeps the religion to a minimum. The religious references are always to the "old" god or saint Mortain. The nuns serve the god of death and kill those marked for it. This service ultimately leads the main character to be involved in court intrigue.
I liked the main characters, Ismae and Duval. Although Ismae vacillated far too much with her feelings on situations and people. The more minor characters were well drawn and you came to care for them as well. As for the romance between Ismae and Duval, I would not call it much of a romance. It is subtle and lacking in any real warmth, especially due to Ismae being torn between her "duty" and her feelings. Also, despite being an assassin, Ismae does not perform nearly as many as one would think throughout the novel. Having the major setup in the beginning, her training and such, lead to so little in the end was frustrating.
I was a bit confounded by the fact that Ismae worked with poisons but had no knowledge of specific antidotes. Surely things can go wrong and one would need such a backup? Do the nuns truly feel their trainees are infallible? I think not, judging by their criticisms in the book.
Overall it was an entertaining novel but had lulls and valleys. I enjoyed the characters but not Ismae and Duval's relationship.