"I guess you're clean, Burland," he admitted, and then turned to the others. "But I'm finding whatever was in Biggert's hand, understand? Mr. Weedham, you'll go call headquarters and tell them I want the Homicide Detail out here." "You mean me, d-d-don't you?" Jeff Weedham asked. McGinty shook his head. "I mean your father. You and the rest stay here. I'll have a little more searching to do. And a lot more questions to ask." Though McGinty fulfilled his promise in so far as the questions and the searching were concerned, he didn't turn up the piece of paper he was looking for. Neither did he find the weapon or the murderer. It was about eleven o'clock when Jack Carlson asked permission to leave. He had some urgent business to attend to, he explained to the sergeant. McGinty had no grounds for holding Carlson, told him to go ahead. But Carlson did not leave alone. Kip Burland, without asking permission from anybody or even saying good-night to Barbara, slipped quietly from the house. He was particularly interested in the urgent business which was pressing Mr. Jack Carlson. CHAPTER VII _The Trail Of The Beam_ If Jack Carlson was as innocent as he pretended to be, it was curious that he should stop just outside the gate of the Weedham home, reach into a bed of dwarf evergreens from which he took a long copper cylinder which closely resembled a flashlight. From his hiding place in the shadows, Kip Burland saw this move on the part of Carlson. He then saw Carlson get into his car and drive away. Burland hailed a passing cab, ordered the driver to keep Carlson's car in sight. Carlson drove down into the lower east side of town, parked his car in a narrow street, and got out. Kip ordered his cab to pass Carlson's car. Looking back through the rear window, he saw Carlson turn up a narrow walk between two tenement buildings. "Stop here," Kip ordered the cab driver. And as the taxi braked, he got out, threw a bill to the driver, and ran up the street toward the place where Carlson had disappeared. In the dusky shadows between the two tenements, Burland watched Carlson put something into a wooden milk box attached just outside what was apparently someone's kitchen door. Then Kip had to duck back into a darkened doorway as Carlson retraced his steps, and got back into his car. Kip had to make a choice quickly. Either he continued to follow Carlson or he investigated the milk box which Carlson had mysteriously visited. In as much as there was no taxi in sight, Kip decided on the latter course. As soon as Carlson was out of sight, he left the doorway, went up the walk between the two buildings, opened the milk box. Inside the box he found the copper cylinder which he had seen Carlson take from its hiding place outside the Weedham home. The thing resembled a flashlight more closely than ever on close inspection. It was a little longer than the usual three cell case, and there was a finely ground lens at the end.