School prefects at Wrykyn did weekly essays for the headmaster. Thosewho had got their scholarships at the 'Varsity, or who were going up inthe following year, used to take their essays to him after school andread them to him--an unpopular and nerve-destroying practice, akin tosuicide. Trevor had got his scholarship in the previous November. Hewas due at the headmaster's private house at six o'clock on the presentTuesday. He was looking forward to the ordeal not without apprehension.

　　The essay subject this week had been "One man's meat is another man'spoison", and Clowes, whose idea of English Essay was that it should bea medium for intempestive frivolity, had insisted on his beginningwith, "While I cannot conscientiously go so far as to say that oneman's meat is another man's poison, yet I am certainly of opinion thatwhat is highly beneficial to one man may, on the other hand, to anotherman, differently constituted, be extremely deleterious, and, indeed,absolutely fatal."Trevor was not at all sure how the headmaster would take it. But Cloweshad seemed so cut up at his suggestion that it had better be omitted,that he had allowed it to stand.

　　He was putting the final polish on this gem of English literature athalf-past five, when Milton came in.

　　"Busy?" said Milton.

　　Trevor said he would be through in a minute.

　　Milton took a chair, and waited.

　　Trevor scratched out two words and substituted two others, made acouple of picturesque blots, and, laying down his pen, announced thathe had finished.

　　"What's up?" he said.

　　"It's about the League," said Milton.

　　"Found out anything?""Not anything much. But I've been making inquiries. You remember Iasked you to let me look at those letters of yours?"Trevor nodded. This had happened on the Sunday of that week.

　　"Well, I wanted to look at the post-marks.""By Jove, I never thought of that."Milton continued with the business-like air of the detective whoexplains in the last chapter of the book how he did it.

　　"I found, as I thought, that both letters came from the same place."Trevor pulled out the letters in question. "So they do," he said,"Chesterton.""Do you know Chesterton?" asked Milton.

　　"Only by name.""It's a small hamlet about two miles from here across the downs.

　　There's only one shop in the place, which acts as post-office andtobacconist and everything else. I thought that if I went there andasked about those letters, they might remember who it was that sentthem, if I showed them a photograph.""By Jove," said Trevor, "of course! Did you? What happened?""I went there yesterday afternoon. I took about half-a-dozenphotographs of various chaps, including Rand-Brown.""But wait a bit. If Chesterton's two miles off, Rand-Brown couldn'thave sent the letters. He wouldn't have the time after school. He wason the grounds both the afternoons before I got the letters.""I know," said Milton; "I didn't think of that at the time.""Well?""One of the points about the Chesterton post-office is that there's noletter-box outside. You have to go into the shop and hand anything youwant to post across the counter. I thought this was a tremendous scorefor me. I thought they would be bound to remember who handed in theletters. There can't be many at a place like that.""Did they remember?""They remembered the letters being given in distinctly, but as forknowing anything beyond that, they were simply futile. There was anold woman in the shop, aged about three hundred and ten, I shouldthink. I shouldn't say she had ever been very intelligent, but nowshe simply gibbered. I started off by laying out a shilling on somepoisonous-looking sweets. I gave the lot to a village kid when I gotout. I hope they didn't kill him. Then, having scattered ground-baitin that way, I lugged out the photographs, mentioned the letters andthe date they had been sent, and asked her to weigh in and identifythe sender.""Did she?""My dear chap, she identified them all, one after the other. The firstwas one of Clowes. She was prepared to swear on oath that that was thechap who had sent the letters. Then I shot a photograph of you acrossthe counter, and doubts began to creep in. She said she was certain itwas one of those two 'la-ads', but couldn't quite say which. To keepher amused I fired in photograph number three--Allardyce's. Sheidentified that, too. At the end of ten minutes she was pretty surethat it was one of the six--the other three were Paget, Clephane, andRand-Brown--but she was not going to bind herself down t............