tement with interest.

"Indeed?" he said, when Mr. Downing had finished.

"Indeed? Dear me! It certainly seems--It is a curiously well-connected
thread of evidence. You are certain that there was red paint on this
boot you discovered in Mr. Outwood's house?"

"I have it with me. I brought it on purpose to show to you. Smith!"

"Sir?"

"You have the boot?"

"Ah," said the headmaster, putting on a pair of pince-nez, "now let me
look at--This, you say, is the--? Just so. Just so. Just.... But, er,
Mr. Downing, it may be that I have not examined this boot with
sufficient care, but--Can _you_ point out to me exactly where
this paint is that you speak of?"

Mr. Downing stood staring at the boot with a wild, fixed stare. Of any
suspicion of paint, red or otherwise, it was absolutely and entirely
innocent.

CHAPTER L

THE DESTROYER OF EVIDENCE

The boot became the centre of attraction, the cynosure of all eyes.
Mr. Downing fixed it with the piercing stare of one who feels that his
brain is tottering. The headmaster looked at it with a mildly puzzled
expression. Psmith, putting up his eyeglass, gazed at it with a sort
of affectionate interest, as if he were waiting for it to do a trick
of some kind.

Mr. Downing was the first to break the silence.

"There was paint on this boot," he said vehemently. "I tell you there
was a splash of red paint across the toe. Smith will bear me out in
this. Smith, you saw the paint on this boot?"

"Paint, sir!"

"What! Do you mean to tell me that you did _not_ see it?"

"No, sir. There was no paint on this boot."

"This is foolery. I saw it with my own eyes. It was a broad splash
right across the toe."

The headmaster interposed.

"You must have made a mistake, Mr. Downing. There is certainly no
trace of paint on this boot. These momentary optical delusions are,
I fancy, not uncommon. Any doctor will tell you----"

"I had an aunt, sir," said Psmith chattily, "who was remarkably
subject----"

"It is absurd. I cannot have been mistaken," said Mr. Downing. "I am
positively certain the toe of this boot was red when I found it."

"It is undoubtedly black now, Mr. Downing."

"A sort of chameleon boot," murmured Psmith.

The goaded housemaster turned on him.

"What did you say, Smith?"

"Did I speak, sir?" said Psmith, with the start of one coming suddenly
out of a trance.

Mr. Downing looked searchingly at him.

"You had better be careful, Smith."

"Yes,