The Pet Show Mystery

room, closing the door behind her.
    As she passed Mart’s room, she heard him say, in an exasperated voice, “I don’t get this at all!”
    Softly, Trixie walked into his room. “Your program still isn’t working,” she said sympathetically.
    “It’s working perfectly,” Mart said. “That’s what I don’t understand. I had such a confusing crazy quilt of corrections that I decided to go right back to the beginning. So I put the program in the same way I did two weeks ago at school, without any of the changes or modifications I’ve made since then—and now it works!”
    “You must have done something differently, if it works now and didn’t then,” Trixie insisted.
    “No, I put this exact same program in the computer,” Mart said stubbornly. “It took me the whole hour. The next morning I came in and tried to run it, and—” Mart suddenly jumped to his feet, backing away from the computer as if it might be about to explode. “There’s only one explanation. Somebody sabotaged my program after I left the computer room!”
    Mart continued to stare at the computer. He stood with his feet wide apart, his shoulders pulled back, and his arms held stiffly out from his sides. It was, Trixie realized, the posture of a cowboy who was about to draw a six-gun and shoot down a villain.
    That ridiculous thought snapped the tension that Trixie had been feeling all evening.
    Suddenly, uncontrollably, she started to laugh.
    Mart whirled and looked at her furiously. “What’s so funny about someone sabotaging my program?” he demanded.
    Somehow, Mart’s rage made the whole thing seem even funnier. “N-nothing,” Trixie said, her laughter contradicting the denial. “I’m sorry. It’s been one of those days, I guess. But are you sure someone sabotaged the pro-gram r
    “How else do you explain it?” Mart asked. “This is the same program I typed into the computer two weeks ago. It works perfectly now, but it sure didn’t then. That’s why I’ve spent all this time trying to get the bugs out of it.”
    “But who would have done such a thing, and why?”
    “I don’t know why, but I do know who,” Mart said grimly. “It would take a lot of knowledge about computers to ruin the program without my being able to spot the sabotage. There’s only one person in my class who knows enough to do such a thing.”
    “Gordon Halvorson!” Trixie exclaimed.
    “Gordon Halvorson,” Mart confirmed.
    “But why?” Trixie pressed. “I thought Gordon was so eager to teach you about computers.”
    “That’s how he’s been acting,” Mart said. “But maybe he was being helpful as an excuse to hang around and make sure I didn’t get the program working.”
    “Oh, but Mart, I can’t imagine—” Trixie broke off as Brian Belden walked into the room.
    “Still having problems with your program?” he asked.
    “Not anymore,” Mart said. “There’s a different kind of problem now.” Briefly, he told Brian what he’d concluded.
    Brian let out a soft, low whistle. “So that’s the story,” he said. “Well, it’s a relief. I was beginning to think you weren’t as smart as you’ve been telling me you were.”
    “Terrific—another comedian,” Mart said.
    “This isn’t funny, Brian Belden,” Trixie said, forgetting that she had been laughing at Mart just a few minutes earlier. “Gordon deliberately sabotaged the program. What he did was wrong. Somebody has to make sure he doesn’t try it again.”
    “You’re right, Trixie. I apologize, Mart. I guess I just wanted your programming problems to be over, so that we could concentrate full-time on the pet show and on finding Reddy. But you’re right—Gordon has to be confronted.”
    Mart sank back down into his desk chair. He reached around to the back of the computer and pushed the off switch. The screen instantly went blank, but Mart continued to stare at it. “At least I’ve seen the last of that program,” he said.
    “The last of it?” Trixie shrieked. “Getting it working was just the beginning. Now you have to put all the data from all the pets into it.”
    Mart’s jaw dropped open. He turned in his chair and stared dumbly at Trixie.
    Again, Brian and Trixie began to laugh.
    Mart wasn’t amused. He rose, zombie-like, from his chair. “I’m going to bed,” he announced.
    “Sweet dreams,” Trixie said in a syrupy voice. Then, bursting into laughter once again, she left her brother’s room and headed for her own.
    Alone in her