N or M?

I have been working my way through Christie's mysteries chronologically and have been looking forward to the next Tommy and Tuppence for a long time. If you haven't read The Secret Adversary and Partners in Crime (short stories) I would suggest reading them first because you will already be fond of the characters. It's fun to see where they are 20 years later and see them still up to the same adventures.

This one is more of a spy novel and takes place when it was written—in 1941 in the midst of WWII. It is interesting and impressive looking at it in retrospect because Christie had no idea what would happen in the years to come. There are mentions of infiltrating spies, concentration camps, Dunkirk...all things we know far more about now than she did then.

The plot follows Tommy and Tuppence as they try to uncover the identity of one of two of Germany's most dangerous spies—either N or M. They are staying undercover in a boardinghouse in a strategic location in England where they think the spy is hiding out. This plot is a lot more active than many of her books, which is refreshing after Poirot asking different people questions for several novels.

I think she showed her hand a bit too soon, since I figured it out (without question) about half way through the book. But besides being angry at how obtuse the characters are, I still loved how the ending plays out. It's action packed and full of surprises.