had lunch in his brown suit, and the servants had noticed it,
Cayley could always have pretended that he had changed into blue
after lunch, because only Cayley saw him afterwards. So if
Cayley had told the Inspector that he was wearing blue, Mark
could have escaped quite comfortably in his brown, without
needing to change at all."

"But that's just what he did do," cried Bill triumphantly. "What
fools we are!"

Antony looked at him in surprise, and then shook his head.

"Yes, yes!" insisted Bill. "Of course! Don't you see? Mark did
change after lunch, and, to give him more of a chance of getting
away, Cayley lied and said that he was wearing the brown suit in
which the servants had seen him. Well, then he was afraid that
the police might examine Mark's clothes and find the brown suit
still there, so he hid it, and then dropped it in the pond
afterwards."

He turned eagerly to his friend, but Antony said nothing. Bill
began to speak again, and was promptly waved into silence.

"Don't say anything more, old boy; you've given me quite enough
to think about. Don't let's bother about it to-night. We'll
just have a look at this cupboard and then get to bed."

But the cupboard had not much to tell them that night. It was
empty save for a few old bottles.