bviously 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.

Passing 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