The Scarlet Letters by Ellery Queen

long,” said Ellery gravely, “heaven only knows. Probably start working backwards from Z.”
    â€œGames,” said Nikki. “Games!”
    â€œBut now the question: How did Martha know that A didn’t stand for the Astor, or the Art Students’ League, or the American Museum of Natural History? And B –why not Bellevue Hospital, or the Broadway Tabernacle, or Battery Park? The B was unqualified, except for time; so was the A . How did she know?
    â€œThe answer is that the initial-letter element of the code must be part of it only. The master key of the code must specify which A -place of all the A -places in New York the letter A in the code is to designate. Harrison has one copy of the decoding instrument, Martha the other. When she gets a message designating C , she’ll simply look up C in her copy, and she’s away.”
    â€œThat first envelope,” said Nikki, “retaining the shape of some booklet!”
    â€œNice work,” grinned Ellery. “Have you kept looking for it?”
    â€œWell–yes.”
    â€œNot, I gather, with the enthusiasm its importance warrants. You see how exacting detective work is, Nikki. You’ve got to find that booklet. It’s probably a guidebook of some sort to places of interest in New York City. With it we’ll know where they’ll meet before they meet. The advantages are self-evident.”
    â€œTonight,” said Nikki through her teeth, “you’re talking like Professor Queen, and I don’t appreciate it. I’ll find the damned thing! What’s that you’ve got there?”
    â€œThis?” Ellery looked up from a little black notebook he had taken from his breast pocket. “This is my case book.”
    â€œCase book?”
    â€œTimes, dates, where they meet, where they go, what they do, to the best of my knowledge and belief … Who knows? It may come in handy.”
    Nikki went off drooping.
    While waiting for the next rendezvous, Ellery thought he might as well settle a point or two.
    He spent all of Tuesday, Wednesday, and Thursday in an apparently aimless round of phone calls and visits to various Broadwayites of his acquaintance. He lunched at Sardi’s and the Algonquin, had dinner at Lindy’s and Toots Shor’s, dropped in at 21 and the Stork, ate a midnight snack at Reuben’s, and by Thursday evening he was far fuller of good food than of digestible information. He might have done better pumping the columnists, but he made broad detours whenever he spotted one. Expert of the painless exploratory technique as he was, he did not dare risk a consultation with the specialists. In fact, the newspapers these days gave him the horrors, and he scanned Winchell and Lyons and Sullivan and the rest with the fears of a man of much guiltier conscience.
    The friendship of Martha Lawrence and Van Harrison was of very recent date. No one Ellery spoke to had ever seen them together, or even separately in the same place, until a few weeks before. On that occasion–Ellery’s informant was Maud Ashton, an old character woman with the acquaintanceship of Elsa Maxwell and the certified circulation of Life –they had both attended the all-night telethon emceed by a round robin of TV comedians in the interest of the recent blood-plasma drive. Martha had been there as one of the Broadway celebrities to supervise the studio blood donations, Harrison as a personality of the theater to entertain the television audience. He had given his famous imitation of John Barrymore, and it had netted so much blood for the drive that Harrison remained for the rest of the night, assisting Mrs. Lawrence.
    â€œThey made such a handsome pair,” Miss Ashton smiled. “I wonder if her husband was at his set.”
    â€œWhy, what do you mean?” asked Ellery.
    â€œNot a blinking thing, Ellery, curse the luck. Of course, Van’s an old reprobate who’ll play Sextus seven