Mr. Downing saw it, but did not immediately recognize it for what it was. What he saw at first was not a clue, but just a mess. He had a tidy soul and abhorred messes. And this was a particularly messy mess. The greater part of the flooring in the neighborhood of the door was a sea of red paint. The tin from which it had flowed was lying on its side 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. A footmark! No less. A crimson footmark on the gray concrete!

Riglett, who had been waiting patiently two yards away, now coughed plaintively. 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 his bicycle from the rack, and presently departed to gladden the heart of his aunt, leaving Mr. Downing, his brain fizzing with the enthusiasm of the detective, to lock the door and resume his perambulation of the cricket field.

Give Doctor Watson a fair start, and he is a demon at the game. Mr.

Downing's brain was now working with a rapidity and clearness which a professional sleuth might have envied.

Paint. Red paint. Obviously the same paint with which Sammy had been decorated. A footmark. Whose footmark? Plainly that of the criminal who had done the deed of decoration.

Yoicks!

There were two things, however, to be considered. Your careful detective must consider everything. In the first place, the paint might have been upset by the groundsman. It was the groundsman's paint. He had been giving a fresh coating to the woodwork in front of the pavilion scoring box at the conclusion of yesterday's match. (A labor of love which was the direct outcome of the enthusiasm for work which Adair had instilled into him.) In that case the footmark might be his.

_Note one_: Interview the groundsman on this point.

In the second place Adair might have upset the tin and trodden in its contents when he went to get his bicycle in order to fetch the doctor for the suffering MacPhee. This was the more probable of the two contingencies, for it would have been dark in the shed when Adair went into it.

_Note two_: Interview Adair as to whether he found, on returning to the house, that there was paint on his shoes.

Things were moving.

He resolved to take Adair first. He could get the groundsman's address from him.

Pa.s.sing by the trees under whose shade Mike and Psmith and Dunster had watched the match on the previous day, he came upon the Head of his house in a deck chair reading a book. A summer Sunday afternoon is the time for reading in deck chairs.

"Oh, Adair," he said. "No, don't get up. I merely wished to ask you if you found any paint on your shoes when you returned to the house last night."

"Paint, sir?" Adair was plainly puzzled. His book had been interesting, and had driven the Sammy incident out of his head.

"I see somebody has spilled some paint on the floor of the bicycle shed.

You did not do that, I suppose, when you went to fetch your bicycle?"

"No, sir."

"It is spilled all over the floor. I wondered whether you had happened to tread in it. But you say you found no paint on your shoes this morning?"

"No, sir, my bicycle is always quite near the door of the shed. I didn't go into the shed at all."

"I see. Quite so. Thank you, Adair. Oh, by the way, Adair, where does Markby live?"

"I forget the name of his cottage, sir, but I could show you in a second. It's one of those cottages just past the school gates, on the right as you turn out into the road. There are three in a row. His is the first you come to. There's a barn just before you get to them."

"Thank you. I shall be able to find them. I should like to speak to Markby for a moment on a small matter."

A sharp walk took him to the cottages Adair had mentioned. He rapped at the door of the first, and the groundsman came out in his shirt sleeves, blinking as if he had just waked up, as was indeed the case.

"Oh, Markby!"

"Sir?"

"You remember that you were painting the scoring box in the pavilion last night after the match?"

"Yes, sir. It wanted a lick of paint bad. The young gentlemen will scramble about and get through the window. Makes it look shabby, sir. So I thought I'd better give it a coating so as to look shipshape when the Marylebone come down."

"Just so. An excellent idea. Tell me, Markby, what did you do with the pot of paint when you had finished?"

"Put it in the bicycle shed, sir."

"On the floor?"

"On the floor, sir? No. On the shelf at the far end, with the can of whitening what I use for marking out the wickets, sir."

"Of course, yes. Quite so. Just as I thought."

"Do you want it, sir?"

"No, thank you, Markby, no, thank you. The fact is, somebody who had no business to do so has moved the pot of paint from the shelf to the floor, with the result that it has been kicked over and spilled. You had better get some more tomorrow. Thank you, Markby. That is all I wished to know."

Mr. Downing walked back to the school thoroughly excited. He was hot on the scent now. The only other possible theories had been tested and successfully exploded. The thing had become simple to a degree. All he had to do was to go to Mr. Outwood's house--the idea of searching a fellow master's house did not appear to him at all a delicate task; somehow one grew unconsciously to feel that Mr. Outwood did not really exist as a man capable of resenting liberties--find the paint-splashed shoe, ascertain its owner, and denounce him to the headmaster. There could be no doubt that a paint-splashed shoe must be in Mr. Outwood's house somewhere. A boy cannot tread in a pool of paint without showing some signs of having done so. It was Sunday, too, so that the shoe would not yet have been cleaned. Yoicks! Also tally-ho! This really was beginning to be something like business.

Regardless of the heat, the sleuth-hound hurried across to Outwood's as fast as he could walk.

20

A CHECK

The only two members of the house not out in the grounds when he arrived were Mike and Psmith. They were standing on the gravel drive in front of the boys' entrance. Mike had a deck chair in one hand and a book in the other. Psmith--for even the greatest minds will sometimes unbend--was wrestling with a Yo-Yo. That is to say, he was trying without success to keep the spool spinning. He smoothed a crease out of his waistcoat and tried again. He had just succeeded in getting the thing to spin when Mr.

Downing arrived. The sound of his footsteps disturbed Psmith and brought the effort to nothing.

"Enough of this spoolery," said he, flinging the spool through the open window of the senior day room. "I was an a.s.s ever to try it. The philosophical mind needs complete repose in its hours of leisure. h.e.l.lo!"

He stared after the sleuth-hound, who had just entered the house.

"What the d.i.c.kens," said Mike, "does he mean by barging in as if he'd bought the place?"

"Comrade Downing looks pleased with himself. What brings him around in this direction, I wonder! Still, no matter. The few articles which he may sneak from our study are of inconsiderable value. He is welcome to them. Do you feel inclined to wait awhile till I have fetched a chair and book?"