- First published: USA: Dodd Mead, 1941; UK: Collins, November 1941
Christie’s only book of the period to directly concern WWII is a thriller, in which N and M, Hitler’s most trusted agents, direct Fifth Column activities from a seaside resort prior to the invasion of England, a trick they have played before. (If so, how can they have been in Britain long enough to establish themselves? And since Hahn was exposed in 1936, how could his exposer have been on the continent?) Two spies require two detectives, to wit, Tommy and Tuppence, Christie’s often infuriatingly hearty duo, now thankfully subdued. Tommy is decent if rather stupid, and hence fitted to the action stuff, including being knocked out and kidnapped while Tuppence detects. The plot is actually quite straightforward and sensible, with an increase in tension towards the end and a satisfyingly improbable surprise solution.
Here is great news! A new story about the famous pair of sleuths, Tommy and Tuppence Beresford, who successfully solved the ticklish problems described by Mrs. Christie in Partners in Crime. Tommy and Tuppence have a grown-up family now and are feeling a bit out of things until Tommy is given a special assignment to investigate fifth column activities. His whereabouts is supposed to be a secret, even from Tuppence, but it isn’t so easy to keep Tuppence and danger apart, and so they embark together on a very difficult and exciting job. The action takes place in or near a seaside boarding house and Agatha Christie portrays in her own vivid style the inhabitants and their daily lives, and keeps us all on tenterhooks until the last thrilling episode is finished.
Both N and M were dangerous enemy agents during the last War and now one of them was back again, leaving death and destruction in his—or her—wake. When a British Intelligence officer was mysteriously killed in the isolated coastal village of Leahampton, headquarters knew that the trail was getting warm although the clues the dying man left were pitifully slender. Those meagre clues started Tuppence and Tommy Beresford on a startling career. To this enterprising young couple fell the job of tracking down N or M.
The adventures of Tuppence and Tommy in Leahampton and at Sans Souci, the little boarding house connected in some mysterious way with their quarry, combine the sort of frightening suspense which only Agatha Christie can conjure up with the newspaper-fresh background of England at war.
Times Literary Supplement (Maurice Willson Disher, 29th November 1941): MASTER SPIES
To believe that N or M? is not Miss Agatha Christie’s best is difficult while the first fine anxious rapture of her latest story is still troubling the mind. Either of those master spies, N and M, may be staying at a seaside boarding house called Sans Souci. Tommy is sent there secretly by Intelligence and immediately realises that the widow who has designs upon him knows all there is to know about his own affairs. Which of all those tootsies, male or female, can be suspected? Which cannot? There is no difficulty about making a correct guess because each character in turn sheds clues that give cause for alarm. The point is reached when you begin to fear for your own safety on catching yourself wondering whether an ingratiating babe-in-arms might not be Herr Doktor in disguise. Yet such is Miss Christie’s skill in conjuring up the ominous that even infant prattle sounds uncommonly like a code for the Fifth Column. In other words, as Mr. Robey has said before now, N or M? gets you.
New Statesman (Ralph Partridge, 20th December 1941): Now let us give short shrift to the Fifth Column. Mrs. Christie has succumbed to the inevitable. That sentimental couple, Tommy and Tuppence, are resurrected to carry on the good work of counter-espionage which they started in Partners in Crime in the last war. N or M deals with the unearthing of The Menace at a South Coast resort in June, 1940. It is exciting, full of surprises, laced with sentiment, and as good a Fifth Column thriller as is likely to be written. Now, I trust, Mrs. Christie will return to Poirot and business.
Manchester Guardian (E.R. Punshon, 30th December 1941): Deserting detection, abandoning M. Poirot, in N. or M. Mrs. Christie bows, like Miss Fitt, to the necessities of war-time and offers her readers a spy story with a devoted married couple tracking down enemy agents in a seaside boarding-house. Mrs. Christie shows herself as ingenious as ever, and one admires especially the way in which the hero snores himself out of captivity.
Observer (Maurice Richardson): Agatha Christie takes time off from Poirot and the haute cuisine of crime to write a light war-time spy thriller. N. or M. is unknown master Fifth Columnist concealed in person of some shabby genteel figure in Bournemouth boarding-house. Mrs. Christie’s bright young couple, now middle-aged but active as ever, are nearly trapped. Nice surprise finish and all-round entertainment.
Books (Will Cuppy, 22nd June 1941, 180w): Here’s exactly the thing for those who want some fairly dangerous non-combatant war atmosphere, slick spy stuff and a sufficiently baffling puzzle all wrapped up in an attractive package by one who knows all there is to know about such matters.
NY Times (Kay Irvin, 22nd June 1941, 360w): In a story whose mystery and excitement follow not unfamiliar—but always interesting—lines, Agatha Christie has found room for a wit which is both keen and significant.
Sat R of Lit (28th June 1941, 40w): Engaging characters, bright dialogue, capital sea-shore boarding-house scenery, and plenteous thrills—with one or two rather unbelievable bits. Good hunting.
New Yorker (5th July 1941, 50w): Crisp, quick reading in this story, but the reader should be able to put his finger on the guilty parties about halfway through the book.
Sunday Times: Here is excellent entertainment with a pretty puzzle for any who take their fun seriously.