He lifted the exhibits out. The shape of the cast, the monogram on the handkerchief cried out their testimony. Robinson grasped Howells's report and glanced over the fine handwriting. After a time he looked up. "There's the case against you, Mr. Blackburn, and at the least your cousin's an accessory. But why the devil did you come to me and make a clean breast of it?" "Because," Bobby cried, "I didn't know anything about these things being here. Can't you see that?" "That's the trouble," Robinson answered uncertainly, "I think I do see it." "Besides," Graham said, "you're still without the instrument that caused death." "I expect to land it in this room," Rawlins answered grimly. He replaced the drawer and continued to fumble among the clothing it contained. All at once he called out and raised his hand. On the forefinger a tiny red stain showed. "How did you do that?" Robinson asked. "Something pricked me," the detective answered. "Maybe it was only a pin, but it might have been--" Excitedly he resumed his search. He took the clothing from the drawer and threw it to one side. Nothing remained in the drawer. "I guess it must have been a pin," Robinson said, disappointed. But Rawlins took up each article of clothing and examined it minutely. His face brightened. "Here's something stiff. By gad, I believe I've got it!" Concealed in a woollen sack, with the slender shaft thrust through and through the folds, was a peculiarly long, stout, and sharp hat pin. Rawlins drew it out. He held it up triumphantly. "Now maybe we're not getting somewheres! That's the boy that did the trick in both cases, and it's what scratched Mr. Paredes. Maybe you noticed how quickly she came upstairs to hide this when she got in." "Good work, Rawlins," Robinson said. He glanced at Bobby and Graham. "Have either of you seen this deadly thing before?" Bobby wouldn't answer, but after a moment's hesitation Graham spoke: "There's no point in lying, Bobby. Katherine knows nothing of this. I disagree with Rawlins. If she had been working with Paredes, which is unthinkable, she'd never have made such a mistake. She wouldn't have struck him. I have seen her wear such a pin." "If she didn't cut him with it," Rawlins reasoned, "who else could have got it out of here and put it back to-night when she kept her door locked?" "There's no getting around it," Robinson said. "Take charge of these things, Rawlins. Put them in a safe place." "What are you going to do?" Bobby asked. "I'm afraid there's only one thing to do," Robinson answered. "I'll have to arrest you both. One of you used this pin in the old room. It doesn't make much difference which one. You've been working together, and we'll find out about Paredes later." "You're making a terrible mistake," Bobby muttered. "You don't know Katherine or you couldn't suspect her of any share in such crimes. Give me until morning to prove how wrong you are." "What would be the use?" Robinson asked.