N or M?

is a work of detective fiction by Agatha Christie first published in the US by Dodd, Mead and Company in 1941[1][2] and in the UK by the Collins Crime Club in November of the same year.The novel is the first to feature the mature versions of her detectives Tommy and Tuppence, whose previous appearances had been in the adventure The Secret Adversary (1922) and the short story collection Partners in Crime (1929).After the outbreak of the Second World War and many years after they worked for British intelligence, middle-aged Tommy and Tuppence Beresford feel useless and sidelined.Grant suspects that "Song Susie" stands for Sans Souci, a hotel in (fictional) seaside Leahampton (based on Bournemouth), and "N" and "M" are known to be two top German spies, one male and one female."[5] Maurice Richardson in a short review in the 7 December 1941 issue of The Observer wrote: "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 [an] unknown master fifth columnist concealed in [the] person of some shabby genteel figure in a Bournemouth boarding-house ... Christie's bright young couple, now middle-aged but active as ever, are nearly trapped.
UK first edition (November 1941)
Agatha ChristieCrime novelDodd, Mead and CompanyEvil Under the SunThe Body in the Librarydetective fictionCollins Crime ClubshillingssixpencecatechismBook of Common PrayerChristian nameTommy and TuppenceThe Secret AdversaryPartners in CrimeSecond World Warfifth columnistsBournemouthThe Times Literary SupplementMr RobeyThe Observerfifth columnistE.R. PunshonThe GuardianRobert BarnardBletchley ParkDilly KnoxEnigma machineBletchleyMilton KeynesBBC OneDell Books[mapback]Pan BooksHarperCollinsLarge-printRedbookClive UpttonWayback MachineBibliographyUniverseAdaptationsSuperintendent BattleTommy and Tuppence BeresfordLady Eileen "Bundle" BrentSir Henry ClitheringCaptain Arthur HastingsChief Inspector James JappMiss Jane MarpleAriadne OliverHercule PoirotParker PyneMr. Harley QuinRaymond WestSt. Mary MeadThe Mysterious Affair at StylesThe Murder on the LinksThe Man in the Brown SuitThe Secret of ChimneysThe Murder of Roger AckroydThe Big FourThe Mystery of the Blue TrainThe Seven Dials MysteryThe Murder at the VicarageThe Sittaford MysteryPeril at End HouseLord Edgware DiesMurder on the Orient ExpressWhy Didn't They Ask Evans?Three Act TragedyDeath in the CloudsThe A.B.C. MurdersMurder in MesopotamiaCards on the TableDumb WitnessDeath on the NileAppointment with DeathHercule Poirot's ChristmasMurder Is EasyAnd Then There Were NoneSad CypressOne, Two, Buckle My ShoeFive Little PigsThe Moving FingerTowards ZeroDeath Comes as the EndSparkling CyanideThe HollowTaken at the FloodCrooked HouseA Murder Is AnnouncedThey Came to BaghdadMrs McGinty's DeadThey Do It with MirrorsAfter the FuneralA Pocket Full of RyeDestination UnknownHickory Dickory DockDead Man's Folly4.50 from PaddingtonOrdeal by InnocenceCat Among the PigeonsThe Pale HorseThe Mirror Crack'd from Side to SideThe ClocksA Caribbean MysteryAt Bertram's HotelThird GirlEndless NightBy the Pricking of My ThumbsHallowe'en PartyPassenger to FrankfurtNemesisElephants Can RememberPostern of FateCurtainSleeping MurderGiant's BreadUnfinished PortraitAbsent in the SpringThe Rose and the Yew TreeA Daughter's a DaughterThe BurdenPoirot InvestigatesThe Mysterious Mr QuinThe Thirteen ProblemsThe Hound of DeathThe Listerdale MysteryParker Pyne InvestigatesMurder in the MewsThe Regatta MysteryThe Labours of HerculesThe Witness for the Prosecution and Other StoriesThree Blind Mice and Other StoriesThe Under Dog and Other StoriesThe Adventure of the Christmas PuddingDouble Sin and Other StoriesThe Golden Ball and Other StoriesPoirot's Early CasesMiss Marple's Final Cases and Two Other StoriesProblem at Pollensa Bay and Other StoriesThe Harlequin Tea SetWhile the Light Lasts and Other StoriesBlack CoffeeMurder on the NileThe MousetrapWitness for the ProsecutionSpider's WebVerdictThe Unexpected GuestGo Back for MurderFiddlers ThreeAkhnatonChimneysWasp's NestThe Yellow IrisThree Blind MiceButter in a Lordly DishPersonal CallThe Road of DreamsCome, Tell Me How You LiveStar Over BethlehemThe Mousetrap and Other PlaysAgatha Christie's Secret NotebooksAgatha Christie MemorialAgathaThe Unicorn and the WaspAgatha and the Truth of MurderAgatha and the Curse of IshtarAgatha and the Midnight MurdersSee How They RunArchie ChristieMax MallowanAshfield, TorquayGreenway EstateAgatha AwardAgatha Christie Award (Japan)