"Barbara," I began--I knew an appeal to the unaccountable Worth would get me nowhere--"the facts we've got to deal with here are a possible murder, with this lad the last person known--by us, of course--to have seen his father alive. We know, too, that they quarreled bitterly. We know all this. Outside people, men who are interested, and more or less hostile, were aware that Worth needed money--needs it yet, for that matter--a large sum. I suppose it is a question of time when it will be known that Worth came here last night; and when it is known, do you realize what it will mean?" Worth had sat through this speech without the quiver of a muscle, and no word came from him as I paused for a reply. Little Barbara, big eyes boring into me as though to read all that was in the back of my mind, nodded gravely but did not speak. I crossed to the shelves and took down the diary whose leather back bore the date of 1916. As I opened it, finding the place where its pages had been removed, I continued, "You and I know--we three here know--" I included Worth in my statement--"that the crime was neither suicide nor patricide; but it is likely we must have proof of that fact. Unless we find the murderer--" "But the motive--there would have to be motive." Barbara struck right at the core of the thing. She didn't check at the mere material facts of how a murder could have been done, who might have had opportunity. The fundamental question of why it should have been was her immediate interest. "I believe I've the motive here," I said and thrust the mutilated volume into her hand. "Some one stole these leaves out of Mr. Gilbert's diary. The books are filled with intimate details of the affairs of people--things which people prefer should not be known--names, details and dates written out completely. It's likely murder was done last night to get possession of those pages." She went to the desk and glanced over the book; not the minute examination with the reading glass which I had given it; that mere flirt of a glance which, when I had first noticed it the night before at Tait's, skimming across that description of Clayte, had seemed so inadequate. Then she turned to me. "Mr. Gilbert cut these out himself," she pronounced. That brought Worth's head up and his face around to stare at her. "You say my father removed something he had written?" he asked. Barbara nodded. "He never changed a decision--and those books were his decisions."