"Still, that don't prove anything," the other man put in. He belonged to the staff of the private detective agency with which Kirby was dealing. The Wyoming man smiled. "It proves my theory is possible. Knowing Olson, I'm willin' to gamble he didn't sit still on the fire escape an' let that drawn blind shut him off from what was goin' on inside. He was one mighty interested observer. Now he must 'a' known there was a clothes-line on the roof. From the street you can see a washin' hangin' out there any old time. In his place I'd 'a' bopped up to the roof an' got that line. Which is exactly what he did, I'll bet. The line had been tied to the posts with a lot of knots. He hadn't time to untie it. So he cut the rope. It's been spliced out since by a piece of rope of a different kind." "How do you know that's been done since?" the detective asked. "A fair question," Kirby nodded. "I don't. I'll find out about that when I talk with the landlady of the Wyndham. If I'm right you can bet that cut rope has puzzled her some. She can't figure out why any one would cut her rope down an' then leave it there." "If you can show me her rope was cut that night, I'll say you're right," the detective admitted. "And if you are right, then the Swede must 'a' been right here when your uncle was killed." "_May_ have been," Kirby corrected. "We haven't any authentic evidence yet as to exactly when my uncle was killed. We're gettin' the time narrowed down. It was between 9.30 and 9.50. We know that." "How do you know that?" the professional sleuth asked. "Accordin' to your story you didn't get into the apartment until after ten o'clock. It might 'a' been done any time up till then." The eyes of Kirby and Rose met. They had private information about who was in the rooms from about 9.55 till 10.10. The cattleman corrected his statement. "All right, say between 9.30 and 10.05. During that time Hull may have shot my uncle. Or Olson may have opened the window while my uncle lay there helpless, killed him, stepped outa the window again, an' slipped down by the fire escape. All he'd have to do then would be to walk into the Wyndham, replace the rope on the roof, an' next mornin' leave for Dry Valley." The detective nodded. "_If_ he cut the rope. Lemme find out from the landlady whether it _was_ cut that night." "Good. We'll wait for you at the corner." Ten minutes later the detective joined them in front of the drug-store where they were standing. The hard eyes in his cold gambler's face were lit up for once.