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, sir."

"I strongly suspect you of having something to do with this."

"Really, Mr. Downing," said the headmaster, "this is surely improbable.
Smith could scarcely have cleaned the shoe on his way to my house. On
one occasion I inadvertently spilled some paint on a shoe of my own. I
can assure you that it does not brush off. It needs a very systematic
cleaning before all traces are removed."

"Exactly, sir," said Psmith. "My theory, if I may...?"

"Certainly Smith."

Psmith bowed courteously and proceeded.

"My theory, sir, is that Mr. Downing was deceived by the light-and-shade
effects on the toe of the shoe. The afternoon sun, streaming in through
the window, must have shone on the shoe in such a manner as to give it a
momentary and fictitious aspect of redness. If Mr. Downing recollects,
he did not look long at the shoe. The picture on the retina of the eye,
consequently, had not time to fade. I remember thinking myself, at the
moment, that the shoe appeared to have a certain reddish tint. The
mistake...."

"Bag!" said Mr. Downing shortly.

"Well, really," said the headmaster, "it seems to me that that is the
only explanation that will square with the facts. A shoe that is really
smeared with red paint does not become black of itself in the course of
a few minutes."

"You are very right, sir," said Psmith with benevolent approval. "May I
go now, sir? I am in the middle of a singularly impressive passage of
Cicero's speech _De senectute_."

"I am sorry that you should leave your preparation till Sunday, Smith.
It is a habit of which I altogether disapprove."

"I am reading it, sir," said Psmith, with simple dignity, "for pleasure.
Shall I take the shoe with me, sir?"

"If Mr. Downing does not want it?"

The housemaster passed the fraudulent piece of evidence to Psmith
without a word, and the latter, having included both masters in a kindly
smile, left the garden.

Pedestrians who had the good fortune to be passing along the road
between the headmaster's house and Mr. Outwood's at that moment saw
what, if they had but known it, was a most unusual sight, the spectacle
of Psmith running. Psmith's usual mode of progression was a dignified
walk. He believed in the contemplative style rather than