The Origin of Evil by Ellery Queen

pausing only long enough to chuckle to Ellery: ‘A fool and his gluttony are soon parted.’
    Delia Priam … He hadn’t seen her at all. Ellery had rather built himself up to their middle-of-the-night meeting, although he was prepared to be perfectly correct. Of course, she couldn’t know that. By the time he arrived she had returned to her room upstairs. He was glad, in a way, that her sense of propriety was so delicately tuned to his state of mind. It was, in fact, astoundingly perceptive of her. At the same time, he felt a little empty.
    Ellery stared gritty-eyed at Dr. Voluta’s blue back. It was an immense back, with great fat wrinkles running across it.
    He could, of course, get rid of the doctor and go upstairs and knock on her door. There was always a question or two to be asked in a case like this.
    He wondered what she would do.
    And how she looked at six in the morning.
    He played with this thought for some time.
    â€˜Ordinarily,’ said the doctor, turning and reaching for a towel, ‘I’d have told you to go to hell. But a doctor with a respectable practice has to be cagey in this town, Mr. Queen, and Laurel started something when she began to talk about murder at Leander Hill’s death. I know your type. Publicity-happy.’ He flung the towel at the bowl, picked up the vial and the plastic dish, holding them firmly. ‘You don’t have to watch me, Mr. Queen. I’m not going to switch containers on you. Where the devil is that detective? I haven’t had any sleep at all tonight.’
    â€˜Did anyone ever tell you, Doctor,’ said Ellery through his teeth, ‘that you look like Charles Laughton in The Beachcomber ?’
    They glared at each other until a car drew up outside and Keats hurried in.
    At four o’clock that afternoon Ellery pulled his rented Kaiser up before the Priam house to find Keats’s car already there. The maid with the tic, which was in an active state, showed him into the living-room. Keats was standing before the field-stone fireplace, tapping his teeth with the edge of a sheet of paper. Laurel Hill, Crowe Macgowan, and Delia Priam were seated before him in a student attitude. Their heads swivelled as Ellery came in, and it seemed to him that Laurel was coldly expectant, young Macgowan uneasy, and Delia frightened.
    â€˜Sorry, Lieutenant. I had to stop for gas. Is that the lab report?’
    Keats handed him the paper. Their eyes followed. When Ellery handed the paper back, their eyes went with it.
    â€˜Maybe you’d better line it up for these folks, Mr. Queen,’ said the detective. ‘I’ll take it from there.’
    â€˜When I got here about five this morning,’ nodded Ellery, ‘Dr. Voluta was sure it was food poisoning. The facts were these: Against Voluta’s medical advice, Mr. Priam invariably has something to eat before going to sleep. This habit of his seems to be a matter of common knowledge. Since he doesn’t sleep too well, he tends to go to bed at a late hour. The cook, Mrs. Guittierez, is on the other hand accustomed to retiring early. Consequently, Mr. Priam usually tells Mr. Wallace what he expects to feel like having around midnight, and Mr. Wallace usually transmits this information to the cook before she goes to bed. Mrs. Guittierez then prepares the snack as ordered, puts it into the refrigerator, and retires.
    â€˜Last night the order came through for tuna fish, to which Mr. Priam is partial. Mrs. Guittierez got a can of tuna from the pantry — one of the leading brands, by the way — opened it, prepared the contents as Mr. Priam likes it — with minced onion, sweet green pepper, celery, lots of mayonnaise, the juice of half a freshly squeezed lemon, freshly ground pepper and a little salt, a dash of Worcestershire sauce, a half-teaspoon of dried mustard, and a pinch of oregano and powdered thyme — and placed the bowl, covered, in the refrigerator.