The Cathedral of Fear: 04/11/18
The Cathedral of Fear by Irene Adler is the fourth of the Sherlock, Lupin and Me series. The Adlers are back in France, in the countryside away from the war in Paris. While out exploring Irene is approached by a mysterious woman who says her mother is in danger.
One of the side plots all the way through is that Irene's father isn't her biological father. As these stories are written as pseudo memoirs, this fact has been dropped in all the books but now we're creeping up on when she finds out. By this late in the series, though, it's not really shocking and it just serves as a distraction from the book specific plot.
The other problem with this book is that it's getting hard to believe that the three friends will all show up together every time Irene's family moves. The amount of handwaving needed to get them back together is taking more and more of every book. It's frankly tiresome.