As Ken walked to school that morning he estimated that at least 25 percent of the cars in Mayfield must be out of commission. Some of the men in his neighborhood were in their driveways futilely punching their starters while their engines moaned protestingly or refused to turn over at all. Others were peering under the hoods, shaking their heads, and calling across the yards to their neighbors. In the street, some cars were lugging with great difficulty, but others moved swiftly along without any evidence of trouble. Ken wondered how there could be such a difference, and if some might prove immune, so to speak, to the effect. He had called a meeting of the club in the chemistry laboratory for an hour before the first class. All of the members were there when he arrived. Ken called the meeting to order at once. "I guess you've all heard the news broadcasts, and you know what's happening here in town," he said. "Yesterday you talked about the possibility of collecting samples and analyzing the material of the comet's tail. I don't know what you decided. You can fill me in later on that. The problem is a lot more important now than it was yesterday. "It's beginning to seem as if the presence of the comet may actually be responsible for the wave of mechanical failures. Finding out how and why is just about the biggest problem in the whole world right now." A babble of exclamations and protests arose immediately from the other members of the group. Al Miner and Dave Whitaker were on their feet. Ted Watkins waved a hand and shouted, "Don't tell us you're swallowing that superstitious junk!" Ken held up a hand. "One at a time. We haven't got all day, and there's a lot of ground to cover. Ted, what's your comment?" "My comment is that anybody's got a screw loose if he believes the comet's got anything to do with all those cars being in Art's garage. That stuff went out of fashion after the days of old Salem." Several of the others nodded vigorously as Ted spoke. "I guess we do need to bring some of you up to date on the background material," said Ken. "Joe, tell them what we found last night." Briefly, Joe Walton described the engines they had dismantled. "Something had happened to them," he said, "which had never happened to an engine since Ford drove his first horseless carriage down Main Street." "It doesn't mean anything!" exclaimed Ted. "No matter what it is, we haven't any basis for tying it to the comet." "Can you name any other universal factor that could account for it?" Ken asked. "We have an effect that appears suddenly in Mayfield, Chicago, Paris, and Cairo. Some people say it's the additives in gasoline, but you don't get them showing up simultaneously in all parts of the world. There is no other factor common to every locality where the mechanical failures have occurred, except the comet.