When Woodman had gone, Joan sat down to think the matter over quietly. She was absolutely certain that her stepfather was in no way guilty of the murders; but, after what Woodman had said, it seemed only too clear that he must have been on the spot when one of them at least was committed. That meant that he knew the truth; but, for some reason or other, he had evidently not told the police what he knew. That, Joan felt, was not altogether surprising. Probably the police had somehow got him into one of his rages; and she knew that, if that were so, it was just like him to have refused to say a word. It was more than ever necessary for her to see him and get at the real truth of what he knew. Only if she had that to go upon could she help him; and, as Carter Woodman would do nothing, she felt that she must devote all her energies to clearing him of the suspicion. He would have to have a good lawyer of his own, of course; but Joan must see him, and compel him to bestir himself about his defence. For one thing, he was certain to be in low water; and she must at once promise to pay all the expenses of the case. She admitted to herself that, in the light of what Charis Lang and Woodman had told her, the police seemed to have a strong case against Walter Brooklyn. Her mind went back to Woodman’s words, “After all, somebody must have done it”; and she realised that, for the police “somebody” might mean Walter Brooklyn quite as readily as any one else. She, knowing him as no one besides knew him, might be sure of his innocence; but that was no reason why others should share her conviction. No, if Walter Brooklyn was to escape from the coils in which he was enmeshed, it would be because decisive evidence was forthcoming that he had not committed the murders. And that decisive evidence would have to be deliberately searched for by some one other than the police, who, intent on proving the case against Walter Brooklyn, would not be likely to seek for clues which would invalidate their own case. And, if she did not undertake this task, who would? She felt that the duty was hers. But if, as she was sure, Walter Brooklyn had not committed murder, then who had, and what had her stepfather been doing in Liskeard House that night? It was true that, by Carter’s account, he had denied his presence there; but it did not surprise Joan at all that her stepfather should have lied to the police. If he was determined not to tell what he knew, his only possible course was to deny that he had been present. She would have to point out to him that, as his presence in the house had been definitely established, the only possible course remaining was to tell the police everything that he knew.