For the Doctor Watsons of this world, as opposed to the SherlockHolmeses, success in the province of detective work must always be, toa very large extent, the result of luck. Sherlock Holmes can extract aclue from a wisp of straw or a flake of cigar-ash. But Doctor Watsonhas got to have it taken out for him, and dusted, and exhibitedclearly, with a label attached.

　　The average man is a Doctor Watson. We are wont to scoff in apatronising manner at that humble follower of the great investigator,but, as a matter of fact, we should have been just as dull ourselves.

　　We should not even have risen to the modest level of a Scotland YardBungler. We should simply have hung around, saying:

　　"My dear Holmes, how--?" and all the rest of it, just as thedowntrodden medico did.

　　It is not often that the ordinary person has any need to see what hecan do in the way of detection. He gets along very comfortably in thehumdrum round of life without having to measure footprints and smilequiet, tight-lipped smiles. But if ever the emergency does arise, hethinks naturally of Sherlock Holmes, and his methods.

　　Mr. Downing had read all the Holmes stories with great attention, andhad thought many times what an incompetent ass Doctor Watson was; but,now that he had started to handle his own first case, he was compelledto admit that there was a good deal to be said in extenuation ofWatson's inability to unravel tangles. It certainly was uncommonlyhard, he thought, as he paced the cricket field after leaving SergeantCollard, to detect anybody, unless you knew who had really done thecrime. As he brooded over the case in hand, his sympathy for Dr.

　　Watson increased with every minute, and he began to feel a certainresentment against Sir Arthur Conan Doyle. It was all very well forSir Arthur to be so shrewd and infallible about tracing a mystery toits source, but he knew perfectly well who had done the thing beforehe started!

　　Now that he began really to look into this matter of the alarm belland the painting of Sammy, the conviction was creeping over him thatthe problem was more difficult than a casual observer might imagine.

　　He had got as far as finding that his quarry of the previous night wasa boy in Mr. Outwood's house, but how was he to get any farther? Thatwas the thing. There were, of course, only a limited number of boys inMr. Outwood's house as tall as the one he had pursued; but even ifthere had been only one other, it would have complicated matters. Ifyou go to a boy and say, "Either you or Jones were out of your houselast night at twelve o'clock," the boy does not reply, "Sir, I cannottell a lie--I was out of my house last night at twelve o'clock." Hesimply assumes the animated expression of a stuffed fish, and leavesthe next move to you. It is practically Stalemate.

　　All these things passed through Mr. Downing's mind as he walked up anddown the cricket field that afternoon.

　　What he wanted was a clue. But it is so hard for the novice to tellwhat is a clue and what isn't. Probably, if he only knew, there wereclues lying all over the place, shouting to him to pick them up.

　　What with the oppressive heat of the day and the fatigue of hardthinking, Mr. Downing was working up for a brain-storm, when Fate oncemore intervened, this time in the shape of Riglett, a junior member ofhis house.

　　Riglett slunk up in the shamefaced way peculiar to some boys, evenwhen they have done nothing wrong, and, having capped Mr. Downing withthe air of one who has been caught in the act of doing somethingparticularly shady, requested that he might be allowed to fetch hisbicycle from the shed.

　　"Your bicycle?" snapped Mr. Downing. Much thinking had made himirritable. "What do you want with your bicycle?"Riglett shuffled, stood first on his left foot, then on his right,blushed, and finally remarked, as if it were not so much a soundreason as a sort of feeble excuse for the low and blackguardly factthat he wanted his bicycle, that he had got leave for tea thatafternoon.

　　Then Mr. Downing remembered. Riglett had an aunt resident about threemiles from the school, whom he was accustomed to visit occasionally onSunday afternoons during the term.

　　He felt for his bunch of keys, and made his way to the shed, Riglettshambling behind at an interval of two yards.

　　Mr. Downing unlocked the door, and there on the floor was the Clue!

　　A clue that even Dr. Watson could not have overlooked.

　　Mr. Downing saw it, but did not immediately recognise it for what itwas. What he saw at first was not a Clue, but just a mess. He had atidy soul and abhorred messes. And this was a particularly messy mess.

　　The greater part of the flooring in the neighbourhood of the door wasa sea of red paint. The tin from which it had flowed was lying on itsside in the middle of the shed. The air was full of the pungent scent.

　　"Pah!" said Mr. Downing.

　　Then suddenly, beneath the disguise of the mess, he saw the clue. Afoot-mark! No less. A crimson foot-mark on the grey concrete!

　　Riglett, who had been waiting patiently two yards away, now coughedplaintively. The sound recalled Mr. Downing to mundane matters.

　　"Get your bicycle, Riglett," he said, "and be careful where you tread.

　　Somebody has upset a pot of paint on the floor."Riglett, walking delicately through dry places, extracted ............