N or M?

UK,12mo wraps,p/back,1st edn(?) (n.d. - circa mid 1940s?). [Originally and first published UK,8vo HB+ dw/dj,COLLINS,1941. This edn,a COLLINS MYSTERY novel,No. 162c WHITE CIRCLE POCKET NOVEL series.] VG. No owner inscrptn and no printed price removal to cover - absence of publisher's price.Slightly dulled, otherwise generally clean,matt,card covers: black background with 2 hooded-silhouettes,one green+ black holding a gun,one green+white holding a dagger; green lettering to white circle and the green+ white hooded gunman Crime Club logo to front cover, a PELMAN INSTITUTE advert to it's reverse,rear cover lightly grubbed,with a jewellery company's b/w+green advert,and a further Mars chocolate advert to inside of rear cover. With negligible shelf-wear,bumping or creasing to edges and corners - one small split/closed tear to foot of spine/backstrip's front gutter's fold,but no other major nicks,tears or splits present,no noticeable reading creases to convex spine/backstrip, book with slight lean.Top+fore-edges aged/toned with minimal,sporadic foxing/spotting; contents though,are bright,tight,clean - with ubiquitous page-edge toning,solid and sound - no other intentional dog-ear reading creases to any pages' corners - appears unread apart from my own collation.UK,12mo wraps,p/back 1st edn,5-192pp [paginated] includes XVI (16) chapters; plus [unpaginated] half-title with story precis to reverse,title page with b/w hooded gunman with gun trademark and blank to reverse.
A very uncommon British title from this author,of the contemporary period.
A new story about the famous pair of sleuths,Tommy and Tuppence Beresford,who successfully solved the ticklish problem described by Mrs. Christie in 'Partners in Crime'. They now become involved in one of their most baffling cases in the tense early days of World War II.Hitler's two most trusted agents are in England. N is a man.M is a woman. Both are masters of cunning,deception.and murder.In the unlikely setting of a seaside boarding house inhabited by an innocent-seeming collection of boarders,Tommy and Tuppence get on the trail of a ruthless scheme involving espionage,kidnapping and killing. Please contact seller @ rpaxtonden@blueyonder.co.uk ,because of the lighter weight and the value of this item for correct,insured (where necessary) shipping/P+p quotes - particularly ALL overseas buyers - BEFORE ordering through the order page! N.B. ALL buyers please note,that stocks' actual shipping/P+p costs are adjusted and any difference is refunded,after order's receipt and before the order's despatch,especially if the item(s) are offered either P+p included/FREE.
** N.B. US/Canada customers please be aware: Standard AIRMAIL postage from UK to these destinations can now cost more than the price of any inexpensive book! If speed is not of the essence,then Economy rate is recommended - at approx. anything from a 1/3rd to 1/2 of the standard US AIR quote/rate - sometimes arriving sooner than the 42 days - but not always. **