Tommy and Tuppence Beresford are two of my favorite characters created by Agatha Christie.  Compared to Poirot or Miss Marple, they are somehow more relatable, maybe because they are a married couple with children and so deal with more day-to-day realities of life.  And they are hugely entertaining! 

In N or M? they are in the middle of World War II and they are told that they are just too old to be of any real help in the war effort despite their successes in the last war.  Their son is a RAF pilot and their daughter works in one of the administration offices so T&T feel like they are the only ones sitting home uselessly.  I'm moving into the stage of life where I sometimes feel like I'm running out of time and maybe that is why this book resonates so well with me. When a representative from one of the spy agencies shows up and offers Tommy a job filing papers at a secret compound in Scotland, Tuppence doesn't believe it.  And she's right.  He's actually being sent to a holiday boarding house on the coast to look for a German spy masterminding an imminent invasion.  Imagine his shock when he arrives and Tuppence is already living there, under a false name!

As they sort through the occupants of the guest house, Sans Souci, they encounter a German immigrant, a bluff British ex-military man, a mother with her child, and various other characters, all of whom seem to be exactly who they are and yet all of whom seem suspicious. I really did not know who to suspect until AC revealed it but as always, the clues are there is you can see them.  They, of course, successfully stop the spymaster in ways that I find quite clever.

Tommy and Tuppence are not universally loved by AC readers but I find them pure entertainment and that's what I read fiction for.  They love each other and their children deeply.  They, especially Tuppence, are sharp and clever.  I highly recommend Tommy and Tuppence!