"I can't say. But remember that the middle window was unfastened. Anyone could have entered from the outside and stabbed him." "You forget," said Prelice quickly, "Miss Chent herself confesses to having unfastened the window." "Quite so; but recollect also that she did not know when she entered the library if her uncle was dead or alive. A quarter to ten that was." "But he surely would have made some sign if----" "No!" interrupted Shepworth decisively. "What of the thick white smoke at which everyone jeers? It probably rendered Sir Oliver insensible, as it did Mona." "Can you explain the smoke?" "I cannot, unless Sir Oliver was trying one of his infernal experiments in connection with the next world." "What book was he reading when found dead?" "There were several books open on the desk," explained Shepworth; "one was the first volume of Captain Cook's voyages; another Pierre Loti's 'Reflets sur la Sombre Route'; and the third 'Polly in Polynesia,' some silly book with a silly title by a silly feminine globe-trotter. I expect Sir Oliver had been refreshing his South Sea memory." "Were the books open at pages dealing with any particular subject?" demanded Prelice after a pause. Shepworth considered. "When examining Sir Oliver's body, I glanced down at the open pages, and saw something about Easter Island. I didn't take much notice, as you may guess; but an illustration of the Easter Island statues was displayed in Cook's voyages. But I'll tell you a queer thing, Dorry. Afterwards, when the murder was discovered, the three books were all closed." "That is natural." "I don't agree with you," rejoined Shepworth emphatically; "the desk should have been left in its original untidiness until the police came to take possession. But someone closed those books." "What do you make of it?" demanded Prelice abruptly. "Well, my theory is that someone--I can't say who--wished to prevent the police seeing that Sir Oliver had been reading about Easter Island. Why, I don't know; and perhaps I may be making a mountain out of a mole-hill." "Mole-hills are important on occasions," said Prelice dryly; "witness the death of William III. Easter Island! Easter Island!" he went on in a musing way. "H'm! h'm! h'm! now what the dickens do I know about Easter Island in connection with this case?" But he asked this question in vain. His memory refused to supply information. CHAPTER IV. EVIDENCE FOR THE PROSECUTION.