"It Was a Series of Intangible Clews That Led Me to This Concrete Bit of Lined Paper"

"The Intangible Clew."
By Reita Lambert (?-?).
First appearance: Munsey's Magazine, October 1925.
Short short story (9 pages).
Online at UNZ HERE.

"How Émile Duret Worked on Novel Lines to Solve the Mystery of the Murder of André Garnier"

Congreve assures us that "Music has charms to soothe a savage breast, to soften rocks, or bend a knotted oak"—but in the case of the untimely death of André Garnier, Congreve not-withstanding, music has, in a manner of speaking, moved an otherwise placid individual to commit murder:

WHEN the body of André Garnier was found, one spring morning, with an ornate knife still protruding from the dead man's breast, there was little reason to believe that his murder would be difficult of solution. He was the sort of person whose biography, had it been written, would lead the reader to expect a tragic ending.

. . . During the first few days following the murder it appeared as if the case would make no trying demands upon the police. A few weeks later, however, it was a hardy individual indeed who broached the subject of the Garnier murder to monsieur le préfet.

The gendarmes are indeed baffled, primarily by a surfeit of suspects, nearly all of them of the feminine persuasion:

Preliminary investigations showed, rather appallingly, that there were as many probable reasons for André Garnier's murder as there had been ladies who had temporarily shared his success. It is almost as confusing to discover twenty motives for a crime as to discover none.

Yet they all, even potentially jealous husbands, have rock solid alibis and, upon closer scrutiny, no strong motive for murdering M. Garnier. Exasperated, the chief of police calls in Émile Duret:

M. Duret was a dapper, gentle-mannered little man with a neatly trimmed Van-dyke and a preoccupied manner. After thirty years of notable services to his country, he had ostensibly retired, and was consulted only on occasions when the endeavors of the police had failed of results.

And fail of results they have, primarily because the police haven't bothered to delve as deeply into the circumstances of the case as our dapper sleuth normally does in his investigations:

M. DURET never took up a case where the police had left off. He made it a rule to go back beyond the place where the police had begun.

Patiently and methodically, Duret assembles clues, both tangible and intangible, all of them individually of no apparent importance:

   ~ ". . . André Garnier had been considered a criminal—a despicable thief who stole the output of his fellow worker's souls . . ."
   ~ ". . . he was to meet a new amoureuse at the Claridge that evening, and to dine with her."
   ~ ". . . a dirty-faced, dark-eyed boy digging in a neglected garden with a broken spoon, and singing as he dug . . ."
   ~ ". . . she did not know of her master's return, contrary to his plans, on the evening before she discovered the body . . ."
   ~ ". . . he was eccentric, irresponsible, undependable . . ."
   ~ ". . . She had sung half a dozen bars when Duret's hand clutched the railing before him spasmodically . . ."
   ~ ". . . no notes or sketches of new songs or verse on either piano or desk . . ."
   ~ ". . . he had drunk a full pot of coffee . . ."
   ~ ". . . The cup was on the piano—within easy reach . . ."
   ~ ". . . he left no manuscript . . ."

Comment: "The Intangible Clew" is apparently M. Duret's only case available to us.

The bottom line: "Everyone is a potential murderer — in everyone there arises from time to time the wish to kill — though not the will to kill."
— Hercule Poirot