Published in January 1922 in the United Kingdom and some months later in the United States, The Secret Adversary received promising press. The London Times found it “refreshingly original, the identity of the arch-criminal is cleverly concealed to the very end” while the Daily News thought it “an ingenious and exciting yarn … eminently readable.” The Saturday Review considered it “an exciting story of adventure, full of hair-breadth escapes, and many disappointments if [readers] try to guess the riddle before the author is ready to give them the clue. An excellent story.” The Daily Chronicle summed it up in a manner that prophetically foreshadowed many reviews to come: “It’s an excellent yarn and the reader will find it as impossible as we did to put it aside until the mystery had been faithfully fathomed.”
These verdicts were encouraging because The Secret Adversary was a complete change of style and pace from Christie’s first book. This first decade of her writing career found Christie searching for a formula that suited her talents. Although the whodunit was the type of book with which she was to find fame and fortune she wrote only four of them between 1920 and 1929: The Mysterious Affair at Styles, The Murder on the Links, The Murder of Roger Ack-royd, and The Mystery of the Blue Train. She interspersed each of these with thrillers, which emphasized physical rather then cerebral activity – The Secret Adversary, The Man in the Brown Suit, The Big Four, and The Seven Dials Mystery – and short-story collections – Poirot Investigates, Partners in Crime, and the episodic novel The Big Four, culled from earlier short stories.
The short-story market at the time was enormous and lucrative, with a mass of fiction magazines crowding the bookstalls. The regular appearance of a short story or a series of short stories kept an author’s name in the public consciousness and, more important for the writer, represented a source of immediate income. Many crime writers appeared regularly in the pages of the multitude of magazines available – Conan Doyle and Sherlock Holmes, Chesterton and Father Brown, Bailey and Mr. Fortune, Hornung and Raffles – and in many cases the appearance of a new story by a favorite writer was a selling point, with the name and title emblazoned on the cover. During this decade Christie wrote an enormous number of short stories for this market; most of them would subsequently appear in collections published over the next twenty years. So, the adventures of Tommy and Tuppence continued almost immediately after their first book appearance in short-story format.
The second Tommy and Tuppence book, Partners in Crime, was published in 1929. Now happily married, the Beresfords at the request of Mr. Carter from The Secret Adversary set up a detective agency and call themselves, with customary modesty, Blunt’s Brilliant Detectives. In fact, the agency is a cover for the dissemination of vital covert information as the previous owner, Mr. Theodore Blunt, was a spy. By taking over his business Tommy and Tuppence are to keep their eyes and ears open and keep Mr. Carter informed. Although this subplot surfaces from time to time in the course of the individual cases that make up the book, it is never a major, or indeed a convincing, reason for their adventures. Most of the cases undertaken by the pair are clever and entertaining but as an added bonus they tackle each case in the manner of a (then) well-known detective.
Although the collection was published in the United Kingdom in September 1929 the individual stories had appeared up to six years previously, mainly in The Sketch, the same magazine in which one Hercule Poirot first made his short-story appearance. With the exception of “The Unbreakable Alibi,” which appeared in 1928, all of the other stories appeared in 1923–24; in other words, in the year following the appearance of The Secret Adversary. Collecting them necessitated some rewriting and rearrangement before the book was issued. So for example when, in Chapter One, Tuppence says “Tommy and Tuppence were married … And six years later they were still living together,” this timeframe tallies with the publication of the book and not with the appearance of the original short story.
A major feature of Partners in Crime is the parody/pastiche element. This idea is promoted by Tommy who, in an effort to emulate the great detectives of fiction, invests in a collection of detective stories and decides to solve each case in the manner of one of his heroes. Thus “The Affair of the Pink Pearl” is solved in the manner of R. Austin Freeman’s Dr. Thorndyke, a pioneer in the field of scientific investigation. “The Case of the Missing Lady” is a Sherlock Homes case and indeed more than one case for the sleuth of Baker Street involved a search for a missing person. Although it is much lighter in tone it is difficult, when reading “The Case of the Missing Lady,” not to think of Holmes’ very similarly titled investigation of “The Disappearance of Lady Frances Carfax.” Some of the characters pastiched are forgotten by modern audiences but most crime fans will fondly remember Edgar Wallace who is recalled in “The Crackler”; Father Brown in “The Man in the Mist” (one of the most accurate pastiches in the book); and Roger Sheringham, the creation of Anthony Berkeley, in “The Clergyman’s Daughter.” The persistent Inspector French, breaker of alibis, and the creation of Irishman Freeman Wills Crofts, is recalled in “The Unbreakable Alibi”; and Baroness Orczy’s Old Man in the Corner, whose modus operandi was to study the account of a crime and to solve it without leaving his ABC teashop, is cleverly captured in “The Sunningdale Mystery.” And in a clever piece of gentle self-mockery the last story of the collection features detection in the style of the great Hercule Poirot in “The Man Who Was No. 16,” a sly reference to The Big Four!
N or M? was published in 1941 and was a complete change of pace for both Christie and Tommy and Tuppence. It is set unequivocally in World War II and was written during the early days of the war. Christie alternated the writing of this with the writing of the very traditional whodunit The Body in the Library and explains in her autobiography, “I had decided to write two books at once since one of the difficulties of writing a book is that it suddenly goes stale on you.” It appears that the composition of two totally contrasting books helped to keep each of them fresh.
The Beresfords are at something of a loose end because both their children are involved in war work and communication between them is guarded. When Tommy (and Tommy only) is asked to undertake a mission at the request of a Mr. Grant, actually an ally of their old friend Mr. Carter, he agrees. A very unimpressed Tuppence takes matters into her own hands and when Tommy arrives at his supposedly secret destination it is to find her already installed, complete with a new persona. The setting, a seaside boardinghouse, is very traditional Christie territory and despite the strong presence of spies, secret agents, codes, and covert subversives the question to be answered is not so much Whodunit? but “Who Is the Spy Mastermind,” although with customary Christie ingenuity she manages to include a murder mystery at the same time, and offers clever and unexpected answers to each problem.
After a gap of more than twenty-five years By the Pricking of My Thumbs was the next-to-last adventure for the pair. When we meet Tommy and Tuppence in the book’s opening chapter they are a middle-aged couple chatting over breakfast. Perhaps because Christie herself was now in her late seventies, most of the characters in the book are similarly elderly. A letter from Tommy’s aunt spurs them on to visit her in her retirement home and there Tuppence meets the elderly Mrs. Lancaster with whom she has a peculiar and, in retrospect, sinister conversation concerning the deaths of some other residents. When on a subsequent visit they discover that Mrs. Lancaster is no longer a resident, having been removed by mysterious relatives, their suspicions are aroused and Tuppence decides to investigate.
The conversation with Mrs. Lancaster also contains an extraordinary sequence, one that is repeated almost exactly in two other unconnected Christie titles. In Chapter Two