“How could it be a clue?” Mrs. Gentrie asked, her eyes twinkling.

  “I don’t know,” Rebecca said firmly, “but it might just as well be. Don’t you think so, Delman?”

  Steele’s laugh was magnetic. “Don’t involve me in a family argument,” he said. “I just room here. They take me in as one of the family—but I’m not a charter member. I am not entitled to take part in the discussions.”

  Mrs. Gentrie laughed. “I’ve never drawn the line there, Delman. When you rented that room and asked if you could move in as one of the family, I told you there was only one thing that was absolutely forbidden—and that was the privilege of the telephone.”

  She turned to Mr. Mason, smiling, and said, “We should have three lines in here. What with three children all making dates and scrambling for the phone every time it rings, I sometimes think I’ll smash it—and I can never get to it in the morning or evening to place my orders at the grocer’s or call up my own friends.”

  Rebecca said, “We were talking about the tin, Florence.”

  Junior said, “Your clutch is slipping, Aunt Rebecca. How the heck could an empty tin have anything to do . . .”

  “Junior!” Mrs. Gentrie broke in. “No one asked you for your opinion. Come on, Mr. Mason, down this way.”

  They all trooped after the lawyer down to the cellar. Mason looked the place over. Mrs. Gentrie pointed out where she had found the tin. Junior showed him the door leading to the garage. Mason tested the paint with his finger. “This what Mr. Gentrie painted last night?” he asked.

  “A quick-drying enamel of some sort,” Steele said by way of explanation. “Mr. Gentrie runs a hardware store, you know. This was a sample of a new brand of paint one of the salesmen for a paint company had given him. He wanted him to try it out. He was telling me about it last night.”

  “It’s necessary to mix it?”

  “Half and half with some thinner,” Steele explained. “Gentrie seemed to think it was a distinct improvement over any other of the brands he’d been handling. It comes in two cans. One of them has the color; and the other is some sort of a quick-drying thinner. You mix the two together, half and half, and apply. It’s supposed to dry within six hours.”

  Mason indicated a spot near the garage door. “Someone evidently didn’t know it had been freshly painted. It looks very much as if someone, groping for the doorknob in the dark, got his hands on the paint.”

  “It does for a fact,” Steele said.

  “Let me see,” Junior insisted, pushing forward with an eager curiosity.

  Steele said, “That’s odd. I hadn’t noticed that before. I was down here with the police, too. It’s just a little smear.”

  Mason said, “The paint’s dry now. You say it dries in six hours?”

  “Yes, four to six hours. That’s what Mr. Gentrie told me. Of course, that’s the only way I have of knowing.”

  “Let’s look for that tin,” Rebecca said, moving along the workbench, sniffing and peering at the assortment of tools. “Here’s a can with paint brushes in it. Could this be it, Delman?”

  “That’s it,” Delman said. “You can always tell the way Mr. Gentrie opens a can. He never runs the opener all the way around. He stops just before he cuts the lid entirely free. He always leaves a strip of tin of about a sixteenth of an inch, then twists the lid off.”

  “That’s right,” Mrs. Gentrie confirmed. “He says that if you go farther than that, the top of the can falls down on the inside. I always hold up the lid and then finish cutting. Arthur twists. You can see where the top of this can was twisted off.”

  Mason thoughtfully regarded the tin. “Let’s take a look at the top of the can just to make our investigation complete,” he said.

  “At the top of the can!” Mrs. Gentrie asked.

  Mason nodded.

  “Well, probably we can find it if we look through this box of scraps, but, for the life of me, I can’t see what. . .”

  Steele said, “I noticed it lying here on the bench last night. There it is, over there near the corner. He used it to set a paint can on.”

  Mason picked up the circular tin top and examined the distinctive place where it had been twisted off.

  “This the one?” he asked.

  “That’s it,” Steele said. “I remember that little distinctive twist on the tin. You can see where it was turned . . .”

  Mason’s eyes showed keen interest. “Wait a minute,” he said. “This isn’t right.”

  “What’s wrong with it?”

  Mason said, “The lid that was on the tin was twisted off to the left. This one is twisted off to the right.”

  Steele bent forward and regarded the circular piece of tin, then went over to look at the can. “Well, I’ll be darned,” he said. “I saw that piece of tin lying here on the counter last night and naturally supposed it had come off this can. Why in the world would Mr. Gentrie have opened the can, thrown the top away, then taken the top from another tin out of that box of scraps? But Gentrie is left-handed. You’re right about that top—but, why . . .?”

  “I don’t know why,” Mason said, “but that’s very evidently what he did. Let’s take a look over here in this box of scraps.”

  Rebecca said tartly to Mrs. Gentrie, “I told you it had something to do with what happened over there. You can see what happens when a trained mind starts working on the problem.”

  Mrs. Gentrie sighed. “I’m afraid I’d make a poor detective,” she said. “It certainly seemed trivial enough.”

  Mason smiled. “I’m afraid I’m like your sister-in-law Mrs. Gentrie. Whenever there’s anything the least bit out of the ordinary, I start making a mystery out of it. After all, you know, it is rather a peculiar place for an empty tin, and I can’t imagine why anyone would seal up an entirely empty tin. There must have been something in it.”

  “Well, I shook it and didn’t hear anything. And goodness knows the can was light enough to be empty. It couldn’t have had anything in it. Of course, now that I see everyone making so much of a point of it, it. . .”

  “And unless I’m mistaken,” Mason, who had been leaning over the scrap box, interposed, “this is the top which came off the can.” He reached down into the tangled mass of tin.

  “Watch out you don’t cut your hand in there,” Mrs. Gentrie warned sharply.

  Junior laughed and said, “Mr. Mason doesn’t need to be a detective to tell you’re the mother of three children, Ma. ‘Don’t do this, and don’t do that.’ ”

  Mason straightened up with a piece of tin in his hand, walked over to the can in which the paint brushes were deposited, and held the circular piece of tin over the top so that the little twisted nipple of tin which had been left on the can was placed against the corresponding point on the circular piece.

  “That’s it all right,” Steele said.

  Junior reached out eagerly. “Gee, Mr. Mason, let me take a . . .”

  “Junior,” Mrs. Gentrie rebuked, “don’t interfere with what Mr. Mason is doing.”

  Mason said, “The underside seems to be all scratched up. It feels rough to the touch. Let’s just examine those scratches. We’ll tilt it over here near the window so that the light comes across it from the side, and . . .”

  “It’s a code,” Rebecca shrilled excitedly. “Something written on there . . . scratched on the tin! I knew it! I just knew it! I told you so, Florence. You wouldn’t listen to me, but. . .”

  Mason whipped a pencil from his pocket and tore a sheet of paper from his notebook. “Will someone write these letters as I read them off?” he asked.

  Rebecca said eagerly, “I will.”

  Mason handed her the paper and pencil, tilting the lid, so that he could get a side lighting on the letters as he read.

  “CKDACK CJIAJ DLACC HEDBCE CEIADD GIKADC CLDGBD KFBCH CLGGBJ.”

  Mason took the piece of paper from Rebecca and carefully checked the letters she had written with the original.

  “I don’t see how this could have had anything to do with what happened across the street,” Mrs. Gentrie said, frankly puzzled.

  Mason slipped the sharp-edged circle of tin into the side pocket of his coat. “It may be just a coincidence,” he agreed. “Rather peculiar, that’s all. How many of you heard the shot?”

  “I did,” Mrs. Gentrie said.

  Steele said, “I was sleeping soundly, and was wakened by the noise. I suppose it was all over when I woke up, but I tried to reconstruct what had wakened me, and somehow had the impression there were two shots.”

  “Did you mention that to Lieutenant Tragg—the head of the Homicide Squad?” Mason asked.

  “I don’t think I did,” Steele said. “He seemed quite positive there was only one shot, and I didn’t contradict him. Of course, my impressions were very vague, just trying to recall a noise which has wakened you from a sound sleep. It’s just a vague feeling, anyhow—an echo in the back of the consciousness, if you know what I mean.”

  Mason said, “I know exactly what you mean, and you express it very well indeed. It might be a good plan for you to get in touch with Lieutenant Tragg and tell him that, after thinking it over, you believe it’s very possible there were two shots.”

  “There weren’t,” Rebecca said positively. “Only one. I was wide awake at the time. I thought it might have been a backfire from an automobile or truck. I know there was only one shot.”

  Mason turned to Junior, raised his eyebrows.

  Junior shook his head. “I can’t help you at all. I slept right through the whole commotion. I couldn’t have been in bed very long when it happened either, probably not more than fifteen or twenty minutes.”

  “What time was the shot?”

  “Around twelve-thirty, I believe.”

  “What time did you get to bed?”

  “Ten or fifteen minutes after midnight. I just shed my clothes all over the room and dove into bed. I’d been out with a young lady, and had taken her home. I thought I was going to have to work today, and—well, I just can’t seem to get enough sleep.”

  Mrs. Gentrie said solicitously, “Junior, don’t you think you should tell Mr. Mason with whom you spent the evening?”

  Junior colored. “No,” he said shortly.

  “I noticed that you avoided mentioning her name to that Lieutenant— What’s his name?”

  “Tragg,” Mason prompted.

  “No need of dragging a woman into this,” Junior said hotly.

  “Junior, was it. . .” Mrs. Gentrie started to ask.

  “Don’t you mention any names,” he interrupted with intense feeling. “I don’t want you snooping around in my affairs. It’s bad enough to have Rebecca always camping on my trail. My gosh, I’m grown up and big enough to take care of myself. I don’t go around snooping into your . . .”

  “Junior!”

  “All right, I’m sorry, but don’t you mention any names. I mean that. This is stuff that gets in the papers, and I don’t see that it makes a particle of difference who I was with.”

  Rebecca said, “Well, what are we going to do about that code message on the can? Here we are, standing talking and letting the murderer slip through the fingers of the police.”

  Mason said, “Let’s be certain about that can before we do anything. You feel quite positive you didn’t put it up on that shelf with the preserves, Mrs. Gentrie?”

  “I know I didn’t, and I don’t think Hester did either.

  She’s stupid at times, but certainly not that stupid. Furthermore, I don’t think that can had been there for more than a day or two at the most. I don’t see how it could have . . . well . . .”

  Mason said, “Well, let’s notify Lieutenant Tragg of exactly what happened, and he can draw his own conclusions. After all, that’s his business.”

  Chapter 5

  Seated in his private office, tilted back in the big swivel chair, Mason propped his heels on the corner of his desk, held his interlocked fingers behind his head, and regarded Della Street with a lazy smile.

  “Well,” he said, “this is one case where I have a free hand. Carr says I’m to do everything I can to uncover the truth. It makes no difference who gets hurt.”

  “Even if it’s Karr himself?” she asked, studying him searchingly.

  Mason nodded. His eyes, preoccupied now, were gazing through Della Street out past the walls of the office.

  “You certainly did make that plain enough to him,” she said. “What were you trying to do, frighten him, or make him mad?”

  “Neither. I just didn’t want any misunderstanding—and I wanted to know where I stood. Lieutenant Tragg is no one’s fool. One of the big things which keeps Karr from being rated as a likely suspect is the condition of his legs. Tragg isn’t going to take anyone’s word for that. He’s going to check up on it.”

  “Ask permission to make an examination?”

  “Oh, he won’t be that crude, not unless he gets something else to work on. After all, he’s not in a position to go around offending prominent taxpayers. He’ll go about it in a roundabout way, but he’ll be very thorough. Don’t worry about that.”

  “You think he’ll be suspicious of Karr’s legs?”

  “I would if I were in his place.”

  She laughed. “Well, in a way, you are.”

  Mason took his hands from behind his head, stretched out his left wrist, and consulted his strap watch. “Paul Drake’s late. He said he’d be in here ten minutes ago, and make a preliminary report. He . . . here he is now.”

  Della Street was up out of her chair as soon as Paul Drake’s distinctive knock sounded on the door of the private office. She crossed over and opened it.

  Paul Drake, head of the Drake Detective Agency, tall, thin, and with a look of perpetual, puzzled perplexity on his face, said, “Hello, gang.”

  “Come in and sit,” Mason invited.

  Della Street picked up her notebook, settled herself at a small secretarial table, and held her pen poised. Paul Drake slid into the big leather chair, squirmed around so that he was seated crosswise, took a notebook from his pocket, and said, “Well, it looks like one of those things.”

  “How so?”

  “The reason Lieutenant Tragg wasn’t particularly communicative,” Drake said, “is that he’s running around in circles. He doesn’t want to talk with anyone until he knows more what he has to talk about.”

  “Let’s have it,” Mason said.

  “I’m somewhat the same way myself, Perry. I’ve picked up as much as I can of what the police know and done a little snooping on my own.”

  “What did you find out?”

  “This man Hocksley is a mystery. I think Opal Sunley, that stenographer who comes in to transcribe the cylinders he dictates, knows more than she’s admitting. I think Mrs. Perlin, the housekeeper, knew a whole lot more than was good for her.”

  “Just what did Hocksley do?”

  “No one knows. Apparently he slept most of the day and spent the nights dictating. He’d use a dictating machine. The girl would come in and find anywhere from two to fifteen records waiting to be transcribed. Sometimes she’d have an easy day. Sometimes she’d have a hard day. Occasionally she wouldn’t be able to even finish the work that was laid out for her. She says it was virtually all correspondence, and that she didn’t pay much attention to the contents of the letters, simply typed them out, made sure there were no typographical errors, and left them for Hocksley to sign. She also made one carbon copy. She left that for Hocksley. She doesn’t know what he did with them. The point is there aren’t any files in the house, just a dictating machine, a cylinder-shaving machine, a transcribing machine, cylinders, a big stock of stationery, envelopes, postage stamps, a pair of scales, and that’s about all in the line of office equipment—except the safe.”

  “What about the safe?”

  “The safe is apparently the key to the whole situation,” Drake said.

  “Tragg seemed very evasive about that safe when I talked with him,” Mason said.

  “He would be. It’s a safe that cost money. It stands in the corner of Hocksley’s bedroom. It isn’t the sort of safe you’d pick up second hand somewhere and use to keep the ordinary bunch of office junk. It’s a safe that has individuality and distinction.”

  “What was in the safe?” Mason asked.

  “That’s another thing,” Drake said. “When the police got there, there were fifty dollars in cash, about a hundred dollars in postage stamps, and not another damned thing in the safe.”

  “Was it locked?”

  “It was locked. Opal Sunley gave Tragg the combination.”

  “Then if a burglar had been working on it, he hadn’t done himself any good.”

  “Perhaps not. . . . He could have closed and locked it again.”

  “Well, a hundred and fifty dollars is a hundred and fifty dollars,” Mason said.

  “Uh huh. But the point is, the man who bought that safe didn’t buy it just for postage stamps and chicken-feed currency.”

  “Okay, what about the shooting?”

  “The shooting took place in that room where the safe is,” Drake said. “There’s some chance Hocksley surprised someone trying to get in the safe. It may have been the housekeeper.”

  “How do they know the safe figured in it?” Mason asked.

  “There’s blood on the floor in front of it, quite a little pool. That might indicate that it was a burglar who was shot. But Hocksley is missing, and the housekeeper is missing. There’s a trail of blood drops around through several rooms in the house, and more to the point, there’s blood in Hocksley’s automobile. So you pay your money and take your choice. Either a burglar killed Hocksley and the housekeeper and carted away the bodies, or Hocksley shot a burglar, then put him in the automobile and took him away. The blood in the automobile indicates that the person who had been shot was stretched out on the back seat of the car. That brings us to what seems to be the most logical explanation.”

  “What’s that?”

  “The housekeeper was the one who was trying to get in the safe. Hocksley shot her, wounded her, put her in the automobile, and took her away. Hocksley was a big, strong man who could have picked up the housekeeper and carried her out to the automobile. She was a slender woman in the fifties. She couldn’t have carried him. There were some burnt matches lying on the floor in the corridor of Hocksley’s flat—about half a dozen of them.”