Fool's Gold by Zilpha Keatley Snyder

Barney had finally seen through the old Ty-wanese Kid and had enough of him. And without Ty around to egg him on, Rudy was pretty sure he could talk Barney out of the whole gold-mining scheme. Particularly now that there was Heather and the riding lessons to occupy his mind.
    But that same evening—it was Wednesday and Rudy had survived another long afternoon of baby-sitting—he found out differently. Natasha and the M and M’s had gone downtown right after dinner and Rudy was alone in the house, except for Ophelia. After reading the funnies and checking the TV schedule, he decided to call Barney. The conversation had started off about the riding lesson and Heather, but then the subject of Tyler Lewis came up, and it seemed that Barney had been talking to him on the phone.
    â€œYou called Styler up?” Rudy asked, and bit his tongue to keep from asking why.
    â€œYeah,” Barney said. “Just to see how he was getting along. Like, if he had blood poisoning or tetanus or anything. He could have, you know, with all those punctures. Punctures are how you get tetanus.”
    â€œYeah, so I’ve heard,” Rudy said. “Well, did he? Have tetanus?”
    â€œGuess not. He didn’t even want to talk about it. All he wanted to talk about was how he’d figured out a way to solve the lamp problem. You know. The one on his miner’s helmet.”
    â€œYou mean that carbide thing,” Rudy asked. “I did a report on those things once. They were pretty dangerous. They make this flammable gas when water drips into the carbide stuff and then there’s a switch that hits a flint that makes a spark. Then if you’re lucky you get a flame. And if you’re unlucky you get a minor explosion, and maybe burn off your eyebrows.”
    Barney laughed. “Yeah, that’s what Ty found out. He said he singed himself a few times, so he went another route. He kind of smashed the lamp part down and taped a flashlight on top of the helmet instead. He said I ought to fix mine the same way.”
    Rudy felt something heavy hit the bottom of his stomach with a thud. “Yours?” he asked in what he hoped wasn’t a quavery voice. “You mean, you have one too?”
    â€œNo,” Barney said. “Not yet.”
    Not just “no.” That wouldn’t have been so bad, although something like, “No, and I don’t want one,” would have been even better. But “not yet”? That could only mean one thing.
    The conversation fizzled out after that, and as soon as Rudy hung up the phone he kind of lurched across the room and dropped into a chair at the kitchen table.
    So, the gold-mining scheme was still in the works. He couldn’t believe it. What he found hardest to believe, in fact, was that Barney could still be interested in doing anything at all with Tyler Lewis, now that he’d been shown up as a cement-brained, loudmouthed show-off. And a chicken besides.
    A chicken. Tyler Lewis was a chicken. A strange raging tornado was building up inside Rudy’s head. He crashed his fist down on the table and then jumped up and kicked the chair he’d been sitting in so hard that it tipped over. Across the room Ophelia leaped to her feet and began to bark.
    â€œShut up, you nerdy dog,” Rudy yelled, and stormed out of the kitchen and down the hall. In his own room he collapsed sideways across his bed and covered his face with his arm.
    With Natasha and the girls away it was very quiet in the house. No sound at all at first and then only an occasional whimper from Ophelia, who had followed him into the room and was now snuffling nervously at his feet.
    â€œShut up, Ophelia,” he said again, but this time with a lot less energy. The raging anger was getting away from him, no matter how hard he tried to hang on to it. And the thing was, he knew that when it was gone he was going to start thinking, and that was exactly what he didn’t want