In the setup of this double-barreled locked-room mystery, Smith offers a scenario that wins no points for originality. Everything about the tale’s two murders, and about the investigation of both crimes, might well have come from a book written in 1923 or 1933. Oft-used tropes pile up fast: A brilliant amateur detective named Algy Lawrence is summoned to Querrin House, near the village of Bristley, to prevent some elusive agent—a ghost, or maybe the devil—from killing Roger Querrin, the master of that domain. A supposed curse, traceable to a querulous ancestor, hangs over a particular room at the house, and Querrin plans to tempt fate by ensconcing himself there one night. Inside the room, a dagger hangs over a fireplace mantel. (Paging Dr. Chekov!)
True to form, the room and its immediate surroundings appear to be purpose-built for hosting an impossible crime problem: Its only points of entry are a single door with a newly keyed lock and a set of French windows that can be firmly bolted from inside. Surrounding the room and a passage that leads to it are beds of fresh soil that would show the footprints of any intruder. On the appointed evening, Lawrence and Peter Querrin, Roger’s brother, stand watch at the entrance to the passage. Sergeant Hardinge, from the local constabulary, watches from outside and has a full view of the French windows. Around midnight, a cry rings out, and Lawrence rushes toward the room and uses his gun to shoot open the door. Inside, he and his fellow watchmen find that Roger Querrin has died from a knife wound.
Just as Lawrence begins to make sense of that killing, a second murder occurs in circumstances that seem to defy explanation. Simon Turner, an old family retainer who nurses a grudge against the Querrins, was caught prowling around the house and has been cooling his heels at the police station in Bristley. Somehow an agent of death manages to strangle him, even though all routes to his cell were under guard during the period when the killing could have taken place.
The solutions that Lawrence offers for these howdunit puzzles aren’t exactly elegant, but they are the best thing about the book. Both of them are plausible (or as plausible as such solutions can be), fairly clued, and wondrously intricate. The whodunit element is impressive, too, and it unfolds as a remarkably elaborate feat of misdirection. (The sequence in which Lawrence adduces answers to both the “who” and the “how” conundrums takes up roughly one-fifth of the novel.) Smith, who explicitly avows his debt to John Dickson Carr, delivers a plot that stands a cut or two above the average Carr tale in this vein. His handling of certain basics of storytelling, however, falls well below the Carr standard. He peoples his stock situations with stock characters who communicate mainly by exchanging stock phrases. The women of the piece, moreover, fall short of being even one-dimensional. They exist mainly to serve Smith’s own prurient interests, and his treatment of them dates the novel badly.
Near the end of Whistle Up the Devil, one ray of original insight glimmers in the dark-paneled library where Lawrence delivers his summation of the case. Smith, via Lawrence, posits the crime-solving equivalent of Heisenberg’s uncertainty principle: Merely by acting as an observer, an investigator may affect—with dire consequences—the outcome of what he is observing. When Lawrence agreed to stand watch outside the room in which Roger Querrin would ultimately die, he assumed that he could maintain his status as an aloof outsider. In fact, as Lawrence ruefully notes, he became complicit in the violent deed that he aimed to forestall. A sense of the tragic therefore sets this tale apart from most prewar novels of its type. Despite its generally frothy tone, the book at that brief moment echoes other works (certain Ellery Queen titles from the same era come to mind) that reflect a mood of postwar atomic dread.