"Yes."

"And he put it down and you picked it up?"

"Yes."

"Did you happen to notice how many matches were present in the matohbook when you lit your cigarette?"

Klein looked surprised. "I don't know. I didn't pay any attention."

"But, in any case, you tore off one match to light your

cigarette?"

"Oh, yes."

"So that even if it had been a full book of matches to begin with, there would be one missing now. Since this looks like a standard matchbook, with thirty matches, there can't be more than twenty-nine matches in it right now-and maybe less."

"I suppose so."

"And how many matches are there in the book now? Would you look and see?"

Klein paused and then opened the matchbook. He stared at it for quite a while, then said, "It hasn't been touched. It's got all thirty matches in it. Let me count them… Yes, there are thirty."

"But you did pick it up from your table, and you did think it was the matchbook you had used? You didn't pick it up from another table altogether?"

"No, no, it was our matchbook. Or at least I was convinced it was."

"All right. If you gentlemen would care to look at it

now, please do so. If you'll notice, there is no mark on the friction strip, no sign of any match being lighted."

Trumbull said, "You mean that Ottiwell substituted this matchbook for the one that was on the table?"

"I thought such a thing was possible as soon as you said he was passing information, Mr. Trumbull. I agreed with you, Mr. Trumbull, that Mr. Ottiwell would make use of matchbooks. The psychology seemed sound to me. But I also agreed with Mr. Avalon that indirection might be used. It's just that Mr. Avalon did not quite see the possible subtlety of the indirection."

"Being too crooked myself to see clearly," sighed Avalon. "I know."

"By concentrating on his collection," said Henry, "and on his mailing and receiving matchbooks, he had you quite firmly pinned there, Mr. Trumbull. Yet it seemed to me that Mr. Ottiwell was not involved with matchbooks only in connection with his collection. Every time he ate in a decent restaurant, which might be often, he would be near a matchbook. Even if he were with others, it would be easy for him to substitute another matchbook for the one already on the table. Once he and the rest of the party left, a confederate could pick it up."

"Not this time," said Rubin sardonically.;

"No, not this time. When the party left, the table was empty of matchbooks. This leads to some bothersome thoughts. Have you been followed, Mr. Klein?"

Klein looked alarmed. "No! At least-at least-I don't know. I didn't notice anyone."

"Any pocket-picking attempts?"

"No! None that I know of."

"In that case, they may not be sure who took it-after all there were four others at the table besides yourself and Ottiwell; and a waiter might have cleared it, too. Or else they think that a lost matchbook will cause far less trouble than an attempt at retrieval might. Or else I'm all wrong from beginning to end."

Trumbull said, "Don't worry, Klein. I'll arrange to have an eye kept on you for a while."

He then went on. "I see the point you're making,

Henry. There are dozens of these matchbooks in any given restaurant at any given time, all of them identical. Ottiwell could easily have picked up one or two on a previous visit-or a dozen, if he wanted to-and then use them as substitutes. Who would notice? Who would care? And are you suggesting now that that one little substitute matchbook would carry the information?"

"It certainly would seem a strong possibility to me," said Henry.

"Go, little Book! from this my solitude/I cast thee on the waters-go thy way!" muttered Halsted. "That's Robert Southey!"

"But how would it work?" said Trumbull, ignoring Halsted's whispered verse. He turned the matchbook from side to side between his fingers. "It's one match-book, just like all the rest. It says 'Cock and Bull' on it, plus an address and a phone number. Where would there be any information on this one as opposed to others?"

"We would have to look in the right place," said Henry.

"And where would that be?" said Trumbull. "I go by what you said, sir," said Henry. "You said Mr. Ottiwell would be sure to use the matchbook in a way that would involve its unique qualities, and I agree. But what is unique about the message that matchbooks carry? In almost every case, it is just advertising matter, and you'll find such matter in almost any number of other places from cereal boxtops to the inside covers of magazines."

"Well, then?"

"Only one thing is truly unique about a matchbook- and that is the matches it contains. In the standard matchbook there are thirty matches that seem to be arranged in a moderately complicated pattern. If you study the bottom of the matches, though, you will see that there are two pieces of cardboard, from each of which there arise fifteen matches. If you count from left to right, first the back row-as you look at them from the direction of the opened flap-and then the front row, say, you can

give each match a definite and unequivocal number from 1 to 30."

"Yes," said Trumbull, "but all the matches are identical with each other and with the matches in other match-books of the same kind. The matches in this particular matchbook are absolutely standard."

"But do the matches have to stay identical, sir? Suppose you took out one match-any one match. There would be thirty different ways of taking out one match. If you took out two matches, or three, there would be many more additional ways."

"No matches are missing."

"Just a manner of speaking. Tearing out matches would be far too crude a way of differentiating. Suppose certain matches had pinholes in them, or little scratches, or a tiny drop of fluorescent paint on the tips that would show up under ultraviolet light. With thirty matches, how many different patterns could you produce by marking any number, from none at all to all thirty?"

"I'll tell you that," interrupted Halsted. "Two to the thirtieth power, which comes to-oh, a little over one billion; that's billion, not million. And if you also marked or didn't mark the flap just behind the matches, you would double that to two billion."

"Well," said Henry, "if you could give a particular matchbook any number from zero to two billion, such numbers could encode considerable information, perhaps."

"As many as six words, easily," said Trumbull thoughtfully. "Damn!" he shouted, jumping to his feet. "Give me that thing. I'm leaving now."

He left for the cloakroom at a run and was back fumbling into his coat and shouting, "Get your coat, Klein, you're coming with me. I need your statement and you'll be safer."

Henry said, "I may be quite wrong, sir."

"Wrong, hell! You're right; I know you are. The whole thing fits a few items you don't know about… Henry, would you consider getting involved in this sort of thing? I mean, professionally."

"Hey," shouted Rubin, "don't you go taking Henry away from us."

"No fear, Mr. Rubin," said Henry softly, "I find it much more exciting here."

This story first appeared in a slightly shorter version, in the December 1972 issue of Ellery Queen's Mystery Magazine, under the title "The Matchbook Collector." Once again, I consider the magazine title pedestrian.

I'll leave it up to you. The phrase "Go, little Book!" is the beginning of a line from Chaucer and from a poem by Robert Southey, and that line from Southey was satirized very effectively by Lord Byron, so it has meaning in the history of English literature. On top of that, it perfectly expresses the nub of the story in which the little (match) books are sent outward on errands of information.