"As sure as any one can be. And now"--Carroll rose--"I'm tremendously obliged for all the information you've given me. Any time you run across anything more that you think might prove of interest, look me up, will you?" "Sure! Sure!" Barker's tone was almost hearty. "You're a regular feller, Mr. Carroll--a regular feller!" The two detectives departed. Carroll spoke to Cartwright as he passed: "Keep both eyes on that fellow Barker," he ordered curtly. "I'll send Reed up to team with you. Don't let him get away. Nab him if he tries it." Cartwright nodded briefly, and Carroll and Leverage climbed into the former's car. As they rounded the corner, Leverage turned wide eyes upon his professional associate. "Carroll?" "Yes?" "You beat the Dutch!" "How so?" "You didn't swallow that bird's yarn, did you?" "Of course not," answered Carroll calmly. "I didn't think so; but you had me worried, with that innocent look of yours. Me, if I was wantin' to play safe on this case, I'd arrest William Barker _pronto_." "Why?" "Because," snapped Leverage positively, "I think he was mixed up in Warren's murder!" "Aa-ah!" Carroll refused to become excited. "You do?" "Yes, I do. What do you think?" "I think this," answered Carroll. "I think that Mr. William Barker knows a great deal more about the case than he has told!" CHAPTER IX ICE CREAM SODA They drove in silence to headquarters, each man busy with his thoughts. It was not until they were alone in Leverage's sanctum that the subject of the recent interview was again broached. It was Leverage who brought it up, in his characteristically gruff way. "I reckon you're wonderin', Carroll, about what I said back yonder in the car?" "About arresting Barker?" "Yes. I guess you're figuring what I'd arrest him for, eh?" "I'm interested--yes." "I'd arrest him for this." Leverage leaned forward earnestly, his attitude that of a man eager to convince. "Let's admit right off the reel that the skirt in the taxicab croaked Warren. Looks like she did, anyway; but whether she did or not, it's an even bet that there was a man mixed up in it somewhere. And if that man isn't Mr. William Barker, then I'll eat a month's pay." "You're sure there was a man mixed up somewhere?" "Certainly. This murder deal was planned in advance. It must have been. Things couldn't just work out that way. And no woman, no matter how much she wanted to bump Warren off, could think of a thing that complicated. Even if she did think of it, she wouldn't have the nerve to carry it out that way. Ain't I right?" "You may not be right, Leverage; but you're certainly logical." "Good! Now, so far, we ain't got any man in this case except Barker." Carroll shook his head. "You're wrong there." "How?"