There were two reasons why the terrible and, in many ways, incredible Garden murder case—which took place in the early spring following the spectacular Casino murder case[1]—was so designated. In the first place, the scene of this tragedy was the penthouse home of Professor Ephraim Garden, the great experimental chemist of Stuyvesant University; and secondly, the exact situs criminis was the beautiful private roof-garden over the apartment itself.

    It was both a peculiar and implausible affair, and one so cleverly planned that only by the merest accident—or, perhaps I should say a fortuitous intervention—was it discovered at all. Despite the fact that the circumstances preceding the crime were entirely in Philo Vance's favor, I cannot help regarding it as one of his greatest triumphs in criminal investigation and deduction; for it was his quick uncanny judgments, his ability to read human nature, and his tremendous flair for the significant undercurrents of the so-called trivia of life, that led him to the truth.

    The Garden murder case involved a curious and anomalous mixture of passion, avarice, ambition and horse-racing. There was an admixture of hate, also; but this potent and blinding element was, I imagine, an understandable outgrowth of the other factors. However, the case was amazing in its subtleties, its daring, its thought-out mechanism, and its sheer psychological excitation.

    The beginning of the case came on the night of April 13. It was one of those mild evenings that we often experience in early spring following a spell of harsh dampness, when all the remaining traces of winter finally capitulate to the inevitable seasonal changes. There was a mellow softness in the air, a sudden perfume from the burgeoning life of nature—the kind of atmosphere that makes one lackadaisical and wistful, and, at the same time, stimulates one's imagination.

    I mention this seemingly irrelevant fact because I have good reason to believe these meteorological conditions had much to do with the startling events that were imminent that night and which were to break forth, in all their horror, before another twenty-four hours had passed.

    And I believe that the season, with all its subtle innuendoes, was the real explanation of the change that came over Vance himself during his investigation of the crime. Up to that time I had never considered Vance a man of any deep personal emotion, except in so far as children and animals and his intimate masculine friendships were concerned. He had always impressed me as a man so highly mentalized, so cynical and impersonal in his attitude toward life, that an irrational human weakness like romance would be alien to his nature. But in the course of his deft inquiry into the murders in Professor Garden's penthouse, I saw, for the first time, another and softer side of his character. Vance was never a happy man in the conventional sense; but after the Garden murder case there were evidences of an even deeper loneliness in his sensitive nature.

    But these sentimental side-lights perhaps do not matter in the reportorial account of the astonishing history I am here setting down, and I doubt if they should have been mentioned at all but for the fact that they gave an added inspiration and impetus to the energy Vance exerted and the risks he ran in bringing the murderer to justice.

    As I have said, the case opened—so far as Vance was concerned with it— on the night of April 13. John F.-X. Markham, then District Attorney of New York County, had dined with Vance at his apartment in East 38th Street. The dinner had been excellent—as all of Vance's dinners were— and at ten o'clock the three of us were sitting in the comfortable library, sipping Napoléon 1809—that famous and exquisite cognac brandy of the First Empire.[2]

    Vance and Markham had been discussing crime waves in a desultory manner. There had been a mild disagreement, Vance discounting the theory that crime waves are calculable, and holding that crime is entirely personal and therefore incompatible with generalizations or laws. The conversation had then drifted round to the bored young people of post-war decadence who had, for the sheer excitement of it, organized crime clubs whose members tried their hand at murders wherein nothing was to be gained materially. The Loeb-Leopold case naturally was mentioned, and also a more recent and equally vicious case that had just come to light in one of the leading western cities.

    It was in the midst of this discussion that Currie, Vance's old English butler and major-domo, appeared at the library door. I noticed that he seemed nervous and ill at ease as he waited for Vance to finish speaking; and I think Vance, too, sensed something unusual in the man's attitude, for he stopped speaking rather abruptly and turned.

    "What is it, Currie? Have you seen a ghost, or are there burglars in the house?"

    "I have just had a telephone call, sir," the old man answered, endeavoring to restrain the excitement in his voice.

    "Not bad news from abroad?" Vance asked sympathetically.

    "Oh, no, sir; it wasn't anything for me. There was a gentleman on the phone—"

    Vance lifted his eyebrows and smiled faintly. "A gentleman, Currie?"

    "He spoke like a gentleman, sir. He was certainly no ordinary person. He had a cultured voice, sir, and—"

    "Since your instinct has gone so far," Vance interrupted, "perhaps you can tell me the gentleman's age?"

    "I should say he was middle-aged, or perhaps a little beyond," Currie ventured. "His voice sounded mature and dignified and judicial."

    "Excellent!" Vance crushed out his cigarette. "And what was the object of this dignified, middle-aged gentleman's call? Did he ask to speak to me or give you his name?"

    A worried look came into Currie's eyes as he shook head.

    "No, sir. That's the strange part of it. He said he did not wish to speak to you personally, and he would not tell me his name. But he asked me to give you a message. He was very precise about it and made me write it down word for word and then repeat it. And the moment I had done so he hung up the receiver." Currie stepped forward. "Here's the message, sir." And he held out one of the small memorandum sheets Vance always kept at his telephone.

    Vance took it and nodded a dismissal. Then he adjusted his monocle and held the slip of paper under the light of the table lamp. Markham and I both watched him closely, for the incident was unusual, to say the least. After a hasty reading of the paper he gazed off into space, and a clouded look came into his eyes. He read the message again, with more care, and sank back into his chair.

    "My word!" he murmured. "Most extr'ordin'ry. It's quite intelligible, however, don't y' know. But I'm dashed if I can see the connection..."

    Markham was annoyed. "Is it a secret?" he asked testily. "Or are you merely in one of your Delphic-oracle moods?"

    Vance glanced toward him contritely.

    "Forgive me, Markham. My mind automatically went off on a train of thought. Sorry—really." He held the paper again under the light. "This is the message that Currie so meticulously took down: 'There is a most disturbing psychological tension at Professor Ephraim Garden's apartment, which resists diagnosis. Read up on radioactive sodium. See Book XI of the Aeneid, line 875. Equanimity is essential.'...Curious—eh, what?"

    "It sounds a little crazy to me," Markham grunted. "Are you troubled much with cranks?"

    "Oh, this is no crank," Vance assured him. "It's puzzlin', I admit; but it's quite lucid."

    Markham sniffed skeptically.

    "What, in the name of Heaven, have a professor and sodium and the Aeneid to do with one another?"

    Vance was frowning as he reached into the humidor for one of his beloved Régie cigarettes with a deliberation which indicated a mental tension. Slowly he lighted the cigarette. After a deep inhalation he answered.

    "Ephraim Garden, of whom you surely must have heard from time to time, is one of the best-known men in chemical research in this country. Just now, I believe, he's professor of chemistry at Stuyvesant University— that could be verified in Who's Who. But it doesn't matter. His latest researches have been directed along the lines of radioactive sodium. An amazin' discovery, Markham. Made by Doctor Ernest 0. Lawrence, of the University of California, and two of his colleagues there, Doctors Henderson and McMillan. This new radioactive sodium has opened up new fields of research in cancer therapy—indeed, it may prove some day to be the long-looked-for cure for cancer. The new gamma radiation of this sodium is more penetrating than any ever before obtained. On the other hand, radium and radioactive substances can be very dangerous if diffused into the normal tissues of the body and through the blood stream. The chief difficulty in the treatment of cancerous tissue by radiation is to find a selective carrier which will distribute the radioactive substance in the tumor alone. But with the discovery of radioactive sodium tremendous advances have been made; and it will be but a matter of time when this new sodium will be perfected and available in sufficient quantities for extensive experimentation...."[3]

    "That is all very fascinating," Markham commented sarcastically. "But what has it to do with you, or with trouble in the Garden home? And what could it possibly have to do with the Aeneid? They didn't have radioactive sodium in the time of Aeneas."

    "Markham old dear, I'm no Chaldean. I haven't the groggiest notion wherein the situation concerns either me or Aeneas, except that I happen to know the Garden family slightly. But I've a vague feeling about that particular book of the Aeneid. As I recall, it contains one of the greatest descriptions of battle in all ancient literature. But let's see..." Vance rose quickly and went to the section of his book-shelves devoted to the classics, and, after a few moments' search, took down a small red volume and began to riffle the pages. He ran his eye swiftly down a page near the end of the volume and after a minute's perusal came back to his chair with the book, nodding his head comprehensively, as if in answer to some question he had inwardly asked himself.

    "The passage referred to, Markham," he said after a moment, "is not exactly what I had in mind. But it may be even more significant. It's the famous onomatopoeic Quadrupedumque putrem cursu quatit ungula campum—meanin', more or less literally: 'And in their galloping course the horsehoof shakes the crumbling plain.'"

    Markham took the cigar from his mouth and looked at Vance with undisguised annoyance.

    "You're merely working up a mystery. You'll be telling me next that the Trojans had something to do with this professor of chemistry and his radioactive sodium."

    "No. Oh, no." Vance was in an unusually serious mood. "Not the Trojans. But the galloping horses perhaps."

    Markham snorted. "That may make sense to you."

    "Not altogether," returned Vance, critically contemplating the end of his cigarette. "There is, nevertheless, the vague outline of a pattern here. You see, young Floyd Garden, the professor's only offspring, and his cousin, a puny chap named Woode Swift—he's quite an intimate member of the Garden household, I believe—are addicted to the ponies. Quite a prevalent disease, by the way, Markham. They're both interested in sports in general—probably the normal reaction to their professorial and ecclesiastical forebears: young Swift's father, who has now gone to his Maker, was a D.D. of sorts. I used to see both young johnnies at Kinkaid's Casino occasionally. But the galloping horses are their passion now. And they're the nucleus of a group of young aristocrats who spend their afternoons mainly in the futile attempt to guess which horses are going to come in first at the various tracks."

    "You know this Floyd Garden well?"

    Vance nodded. "Fairly well. He's a member of the Far Meadows Club and I've often played polo with him. He's a five-goaler and owns a couple of the best ponies in the country. I tried to buy one of them from him once—but that's beside the point.[4] The fact is, young Garden has invited me on several occasions to join him and his little group at the apartment when the out-of-town races were on. It seems he has a direct loud-speaker service from all the tracks, like many of the horse fanatics. The professor disapproves, in a mild way, but he raises no serious objections because Mrs. Garden is rather inclined to sit in and take her chances on a horse now and then."

    "Have you ever accepted his invitation?" asked Markham.

    "No," Vance told him. Then he glanced up with a far-away look in his eyes. "But I think it might be an excellent idea."

    "Come, come, Vance!" protested Markham. "Even if you see some cryptic relationship between the disconnected items of this message you've just received, how, in the name of Heaven, can you take it seriously?"

    Vance drew deeply on his cigarette and waited a moment before answering.

    "You have overlooked one phrase in the message: 'Equanimity is essential,'" he said at length. "One of the great race-horses of today happens to be named Equanimity. He belongs in the company of such immortals of the turf as Man o' War, Exterminator, Gallant Fox, and Reigh Count.[5] Furthermore, Equanimity is running in the Rivermont Handicap tomorrow."

    "Still I see no reason to take the matter seriously," Markham objected.

    Vance ignored the comment and added: "Moreover, Doctor Miles Siefert[6] told me at the club the other day that Mrs. Garden had been quite ill for some time with a mysterious malady."

    Markham shifted in his chair and broke the ashes from his cigar.

    "The affair gets more muddled by the minute," he remarked irritably. "What's the connection between all these commonplace data and that precious phone message of yours?" He waved his hand contemptuously toward the paper which Vance still held.

    "I happen to know," Vance answered slowly, "who sent me this message."

    "Ah, yes?" Markham was obviously skeptical.

    "Quite. It was Doctor Siefert."

    Markham showed a sudden interest.

    "Would you care to enlighten me as to how you arrived at this conclusion?" he asked in a satirical voice.

    "It was not difficult," Vance answered, rising and standing before the empty hearth, with one arm resting on the mantel. "To begin with, I was not called to the telephone personally. Why? Because it was some one who feared I might recognize his voice. Ergo, it was some one I know. To continue, the language of the message bears the earmarks of the medical profession. 'Psychological tension' and 'resists diagnosis' are not phrases ordinarily used by the layman, although they consist of commonplace enough words. And there are two such identifying phrases in the message—a fact which eliminates any possibility of a coincidence. Take this example, for instance: the word uneventful is certainly a word used by every class of person; but when it is coupled with another ordin'ry word, recovery, you can rest pretty much assured that only a doctor would use the phrase. It has a pertinent medical significance— it's a cliché of the medical profession...To go another step: the message obviously assumes that I am more or less acquainted with the Garden household and the race-track passion of young Garden. Therefore, we get the result that the sender of the message is a doctor whom I know and one who is aware of my acquaintance with the Gardens. The only doctor who fulfills these conditions, and who, incidentally, is middle-aged and cultured and highly judicial—Currie's description, y' know,—is Miles Siefert. And, added to this simple deduction, I happen to know that Siefert is a Latin scholar—I once encountered him at the Latin Society club-rooms. Another point in my favor is the fact that he is the family physician of the Gardens and would have ample opportunity to know about the galloping horses—and perhaps about Equanimity in particular—in connection with the Garden household."

    "That being the case," Markham protested, "why don't you phone him and find out exactly what's back of his cryptography?"

    "My dear Markham—oh, my dear Markham!" Vance strolled to the table and took up his temporarily forgotten cognac glass. "Siefert would not only indignantly repudiate any knowledge of the message, but would automatically become the first obstacle in any bit of pryin' I might decide to do. The ethics of the medical profession are most fantastic; and Siefert, as becomes his unique position, is a fanatic on the subject. From the fact that he communicated with me in this roundabout way I rather suspect that some grotesque point of honor is involved. Perhaps his conscience overcame him for the moment, and he temporarily relaxed his adherence to what he considers his code of honor...No, no, that course wouldn't do at all. I must ferret out the matter for myself—as he undoubtedly wishes me to do."

    "But what is this matter that you feel called upon to ferret out?" persisted Markham. "Granting all you say, I still don't see how you can regard the situation as in any way serious."

    "One never knows, does one?" drawled Vance. "Still, I'm rather fond of the horses myself, don't know."

    Markham seemed to relax and fitted his manner to Vance's change of mood.

    "And what do you propose to do?" he asked good-naturedly.

    Vance sipped his cognac and then set down the glass. He looked up whimsically.

    "The Public Prosecutor of New York—that noble defender of the rights of the common people—to wit: the Honorable John F.-X. Markham—must grant me immunity and protection before I'll consent to answer."

    Markham's eyelids drooped a little as he studied Vance. He was familiar with the serious import that often lay beneath the other's most frivolous remarks.

    "Are you planning to break the law?" he asked.

    Vance picked up the lotus-shaped cognac glass again and twirled it gently between thumb and forefinger.

    "Oh, yes—quite," he admitted nonchalantly. "Jailable offense, I believe."

    Markham studied him for another moment.

    "All right," he said, without the slightest trace of lightness. "I'll do what I can for you. What's it to be?"

    Vance took another sip of the Napoléon.

    "Well, Markham old dear," he announced, with a half smile, "I'm going to the Gardens' penthouse tomorrow afternoon and play the horses with the younger set."