After Bart is caught performing another destructive act, Homer and Marge put him on medication. The boy starts taking Focusyne, an experimental Attention Deficit Disorder drug that at first turns him into the very model of manners and efficiency. But the drug has some strange side effects, and Bart becomes paranoid, ranting that Major League Baseball is using a satellite to read his thoughts. Marge and Homer try to take Bart off Focusyne, but he resists and overdoses. During his Focusyne bender, Bart steals a tank from a nearby army base and shoots a satellite out of the sky. Sure enough, the satellite is controlled by Major League Baseball, but America's hero, Mark McGwire, helicopters into Springfield to assure everyone that nothing suspicious is going on.