"That is what I have not been able to find out," growled Brett. "Mrs. Winthrop told me she had not seen her brother since breakfast. That he went to the Capitol as usual in the morning. She was told on entering the house just before dinner that he would not return for that meal, but they did not state where he was going." "Upon my word it's a very pretty problem," commented Douglas softly. "It is," agreed Brett, rising and slowly pacing the room. He glanced piercingly at Douglas, who was thoughtfully contemplating a life-size portrait of one of Carew's ancestors which hung above the mantel over the fireplace. Douglas Hunter's clear-cut features, broad forehead, and square jaw indicated cleverness and determination. When Douglas smiled the severe lines relaxed and his smooth-shaven face was almost boyish. He had a keen sense of the ridiculous, which prevented him from taking himself too seriously. In the past Brett had conceived a high regard for the other's quick wit and indomitable courage. "This is Senator Carew's study or library," he said, stopping before the desk, "and I was giving the room my special attention when you came in." "Have you met with any success?" inquired Douglas quickly. "So far only one thing--it may be a clew or it may not; under this writing pad I found this blotter," holding up a square white sheet; "it has been used only once, first on one side then on the other, so that by holding it in front of this mirror you can read quite clearly, see----" Douglas rose, stepped behind Brett, and peeped over his shoulder into the silver-mounted mirror, which the latter had removed from its place on the mantel. The large, bold writing was fairly legible. "What do you make out of it?" asked Brett impatiently. Obediently Douglas read the words aloud: "'Am writing in case I don't see you before you'--" the writing ceased. "He must have been interrupted," explained Brett, "and clapped down the blotter on top of the sheet so that whoever entered couldn't see the written words. Now look at the other side," and he turned over the blotter on which were traced only a few words: "'I have discovered----'" read Douglas. "What do you think of it?" asked Brett, putting the blotter in an inner pocket of his coat. "It depends on when it was written"--Douglas' eyes strayed to the door. Surely Brett had closed it when they entered, now it stood partly open into the hall. He pointed silently to it, and by common impulse both men stepped out into the hall. Listening intently they heard a faint rap on one of the doors in the upper hall; then a high-pitched, quivering voice reached them: "Eleanor, Eleanor, I'm so glad you've come. I'm nearly sick with misery. They quarreled, Eleanor, they quarreled----" her voice caught in a sob--the door slammed shut. The two men glanced at each other, their eyes asked the same question. Who quarreled? CHAPTER VI CIRCUMSTANTIAL EVIDENCE