"A man and woman entered the back room by this window," said Ashton-Kirk.
"I don't like to put myself in an attitude of continued protest," said Fuller, "but these low windows are commonly used that way. You see, it's only a step to the lawn."
"As you say," he agreed, "these low windows are commonly used in that way. But only when the rooms into which they open are also in common use."
"I see what you mean," said Fuller. "This back room is private. Old Nanon said the door was always kept locked." He remained gazing at the other for a moment, apparently pondering the new aspect which this discovery gave the situation. "Well, what do you think it means?"
"A woman and a man entered this room by the window; the latter had been left unfastened because it shows not the slightest indication of having been forced. And when they departed, the window was refastened--perhaps not at once, but as soon after as possible."
"You think----" Fuller paused, his eyes wide.
"If you heard a slight noise in the back room while you were in the library, some time after the murder, what would you think?"
"Why, we discussed that this morning," returned Fuller. "It was Drevenoff, beyond a doubt! He waited in the hall after you told him to go to the police station. Then he stole into the rear room and replaced the window catch. And this being so it was he who admitted the woman----"
"And the man?" Ashton-Kirk smiled as he asked the question.
"The man?" Fuller's face grew blank. "Why, the man must have been Warwick! And if it was," after a moment, "why did he require to be admitted to the house by a side window when he could have gone in by the front door?"
If Ashton-Kirk intended to reply to this, he had no time to do so; for at that moment they heard a step behind them and looking around they saw the well-knit figure and expressionless face of Okiu.
The Japanese nodded and smiled in his peculiarly meaningless fashion, the black, intent eyes going from one to the other.
"I was getting a breath of air," said he, "and reading a favorite book, when I happened to see you here. I trust you are well?"
"Quite well," returned Ashton-Kirk, with equal politeness.
Okiu laid a heavy book upon a bench, patting it gently as he did so, as though it were a living thing.
