Anthony’s bedroom looked over the park at the back of the house.  The blinds were not yet drawn while he was changing his clothes for dinner, and at various stages of undress he would pause and gaze out of the window, sometimes smiling to himself, sometimes frowning, as he turned over in his mind all the strange things that he had seen that day.  He was sitting on his bed, in shirt and trousers, absently smoothing down his thick black hair with his brushes, when Bill shouted an “Hallo!” through the door, and came in.

“I say, buck up, old boy, I’m hungry,” he said.

Antony stopped smoothing himself and looked up at him thoughtfully.

“Where’s Mark?” he said.

“Mark?  You mean Cayley.”

Antony corrected himself with a little laugh.  “Yes, I mean Cayley.  Is he down?  I say, I shan’t be a moment, Bill.”  He got up from the bed and went on briskly with his dressing.  “Oh, by the way,” said Bill, taking his place on the bed, “your idea about the keys is a wash-out.”

“Why, how do you mean?”

“I went down just now and had a look at them.  We were asses not to have thought of it when we came in.  The library key is outside, but all the others are inside.”

“Yes, I know.”

“You devil, I suppose you did think of it, then?”

“I did, Bill,” said Antony apologetically.

“Bother!  I hoped you’d forgotten.  Well, that knocks your theory on the head, doesn’t it?”

“I never had a theory.  I only said that if they were outside, it would probably mean that the office key was outside, and that in that case Cayley’s theory was knocked on the head.”

“Well, now, it isn’t, and we don’t know anything.  Some were outside and some inside, and there you are.  It makes it much less exciting.  When you were talking about it on the lawn, I really got quite keen on the idea of the key being outside and Mark taking it in with him.”

“It’s going to be exciting enough,” said Antony mildly, as he transferred his pipe and tobacco into the pocket of his black coat.  “Well, let’s come down; I’m ready now.”

Cayley was waiting for them in the hall.  He made some polite inquiry as to the guest’s comfort, and the three of them fell into a casual conversation about houses in general and The Red House in particular.

“You were quite right about the keys,” said Bill, during a pause.  He was less able than the other two, perhaps because he was younger than they, to keep away from the subject which was uppermost in the minds of them all.

“Keys?” said Cayley blankly.

“We were wondering whether they were outside or inside.”

“Oh! oh, yes!” He looked slowly round the hall, at the different doors, and then smiled in a friendly way at Antony.  “We both seem to have been right, Mr. Gillingham.  So we don’t get much farther.”

“No.”  He gave a shrug.  “I just wondered, you know.  I thought it was worth mentioning.”