Марджери Аллингем - Ellery Queen’s Mystery Magazine. Vol. 14, No. 71, October 1949

“First, you need a list of people who have no personal contact with you at all. That’s easy. Have you never received an advertisement in the mail and wondered how the company got your name and address? Direct mail advertising is big business nowadays. For ten dollars you can buy a few thousand unclassified names. For a hundred dollars or more, you can buy a list of names classified by age, sex, occupation, incomes, tastes, and habits. Lists of people with chronic asthma are prepared for patent-medicine companies — names and addresses sneaked out of hospital and pharmaceutical records.

“You are a mathematician — an astro-physicist, so you are using the law of averages. If you send an attractive-looking box of candied ginger anonymously to several hundred people, there will be at least five or six who will like candy and who will assume the ginger is either a gift from some friend who forgot to enclose his card or a gift sample from some confectioner who wishes to enlarge his trade. You can afford to go slow. You can buy a few boxes every day and you can mail a few every day at several of the substation post offices in the midtown commercial section where hundreds of packages are mailed every day and there is always a long line at the parcel window. No one will notice or remember you. None of your five or six random victims will have reason to suspect poison. Probably each leads a dull, respectable life with no enemies, so each will eat some of the candy you have doctored with datura seeds. The result depends on how much is eaten at one time — another element of chance that will confuse the trail back to you. Some will just have hallucinations. Others will have hallucinations followed by death. The candy is packed in layers with waxed paper between. In the first layer each piece contains enough datura to create illusions without killing, unless the victim is greedy enough to eat many pieces at one time. In the second layer each piece contains a lethal dose. In that way there sure to be some among your victims who will suffer optical delusions first and die a few days later.

“If death is not attributed to the apparent agency of the hallucinations, it will be attributed to the effect of chronic asthma on the heart or to the inhalation of too much stramonium — since that is a remedy for asthmatic spasms.

“You still have two more details to work out — important details. In order to repeat the Flying Disc scare your victims must all see the same hallucination and it must be published in the newspapers. Asthmatics are nervous, susceptible to suggestion. So are people under the influence of a drug. And the Flying Disc scare showed the contagion of an illusion even among normal people. All the murderer needed to do was to plant his suggestion in newspapers.

“Apparently you have forgotten, Mr. Verworn, but Donald MacDonald was a classmate of yours fifteen years ago. Your stepfather looked over alumni records and selected MacDonald for two reasons. He lived alone with two cowhands who would not know your stepfather by sight. He had majored in psychology but economic necessity had made him a rancher in Montana — just as the young man who sets out to be an artist or a poet so often ends as a grocer or a stockbroker. MacDonald was just the man who would be flattered and delighted to participate in what your stepfather must have described to him as ‘a little psychological experiment’ to test the contagion of mass delusions. As an astro-physicist he wished to discover how reliable the layman is in reporting celestial phenomona. Or so he would tell MacDonald.

“Your stepfather had an excuse to go to Canada — he was invited to speak at the graduation exercises at McGill. He went alone — so he could drive across the Border to Montana alone and see MacDonald without anyone else knowing about it. MacDonald was sworn to secrecy. He promised to give a fake story — in apparent good faith — to the nearest newspaper that subscribed to a wire service. A story sufficiently startling to be picked up by that wire service as a sequel to the Flying Discs. Your stepfather gave him precise instructions about the Singing Diamonds — their supernormal speed, their dazzling brightness, their humming sound — all similar to the natural effects of the exaltation which is the first symptom of stramonium poisoning. There was no letter or telephone call to incriminate Anders Verworn. MacDonald himself would not mention the visit. That might spoil the ‘psychological experiment.’

“Before Anders left he promised to send MacDonald a box of candied ginger. And he did send such a box, each piece loaded with a lethal dose of datura, as soon as MacDonald had planted the story so he would never be able to talk about it afterward.

“Once the thing was started, it snowballed. Six of the several hundred victims Anders Verworn had chosen at random were sure they had seen and heard Singing Diamonds — while under the influence, mind you, of the drug without knowing it. Dozens of other unbalanced, suggestible minds were equally sure they had seen and heard Singing Diamonds without any drug at all. In one case a victim gave her box of ginger to her fiancée , a pilot, and in his drugged state he crashed a passenger plane...

“But Anders Verworn made two slips.

“It is said that a man always reverts to the language of his birth at three times — when he prays, when he makes love, and when he counts or does a mathematical problem. When Anders gave instructions to MacDonald, Anders was fearful and excited. So, in calculating the alleged speed of the Singing Diamonds, he gave it to MacDonald as a thousand kilometres an hour instead of a thousand miles an hour. MacDonald realized that the word ‘kilometre’ would rouse suspicion coming from him, so he attempted to translate the velocity into miles. He was stupid enough to translate it literally as “621 miles per hour.” When I saw that figure — 621 — I suspected the story had been planted through MacDonald by a foreigner who thought in kilometres, and I was pretty sure that foreigner was not a Russian, since a thousand Russian versts equals 662.9 miles, not 621.3. For a while my suspicion was evenly divided between you, Mr. Verworn, and your stepfather. Then it settled on him because of his second slip.

“His whole scheme was based on the assumption that his wife would give her story of the Singing Diamonds to the newspapers — so that her death would be one among many that were preceded by hallucinations. But she did not give her story to the papers because she was afraid it would damage her husband’s reputation as an astro-physicist. This bothered him so much that he urged her to talk to reporters. She came to me instead and happened to mention that he had urged her to talk to reporters about it. A man of his training, profession, and published views on the Singing Diamonds should have been opposed most violently to the idea of his wife giving such a story to the press. Naturally I asked myself why he had taken the precisely opposite position — and I began to suspect him.

“Then, when I came here this evening and saw he had access to jimson weed in his own yard, it was a simple matter of association — jimson weed — datura — stramonium — candied ginger — asthma — hallucination — Singing Diamonds. The contrast between a simple housewife like Mrs. Verworn and the beautiful Mrs. Albany supplies an obvious motive. And I knew Mrs. Albany would be the first to drink the coffee after I pretended to drug it. A woman who dresses like that at her age is enviously an exhibitionist. She would drink the coffee before anyone else out of sheer bravado. And I suspected that would put tremendous pressure on Anders Verworn — psychological pressure he could not possibly resist.”