"I don't believe it. Why should he?"
"To give it back to me, presumably."
"He wasn't in that kind of a mood when I last saw him," Mathilda replied. "Besides, if Valerie really left it on the table by her chair, it would have been perfectly safe there. I'll tell you what, Stephen: there's some mystery attached to that case, and for the life of me I can't solve it."
He seemed disinclined to discuss the matter, merely giving a kind of grunt, and turning away to mark up her score on the board. A horrid little doubt seized her: what did she know of him, after all? It might be proved that he was in financial difficulties; he might have taken Nat's threats seriously; he might cherish large desires, which he kept hidden in his own guarded heart, and which only a fortune could put within his reach. There was a streak of cruelty in him, of hard ruthlessness, which was betrayed in his treatment of Joseph, and of Valerie. He didn't care how much he hurt people: he had suffered hurt himself, and that was reason enough for his unkindness to others.
Then her mind veered sharply to the consideration of his sister, and she began to feel that she was living in a world of nightmare. Would Paula be capable of stabbing to death an old man who loved her, merely for the sake of a part in an unknown dramatist's play? She didn't know. She had no clue to Paula either; she only knew her as an urgent, unbalanced young woman, always obsessed by the idea of the moment.
Yes, but although Paula had been seen at Nat's door, how had she contrived to get into a locked room, or, more difficult still, to lock it behind her? Mathilda had no knowledge of the means by which doors could be locked and unlocked from the wrong side, but she knew that there were such means. Yet it seemed unlikely that Paula could have employed any of them, for how could she have acquired the necessary tools?
This led to the question, were they in it together, this odd, frustrated brother and sister? It was too diabolical: Mathilda shied away from the thought, miscued, and straightened herself, saying with a breathless laugh: "Oh, damn! You'll run out now!"
"I wonder what that Scotland Yard man's up to?" Stephen said restlessly.
"Trying to trace the person who handled that dagger," she suggested.
"He won't do that."