The Mystery of the Nebulous Nemesis

When they first see The Nemesis, a notorious roller coaster at a small amusement park in the San Joaquin Valley located right next to Pete's aunt and uncle's citrus grove, The Three Investigators aren't considering anything but helping Pete's family with some trouble they've been having with a government agency. But the government didn't poison the orange trees at the heart of their grove. And why does the Nemesis's owner .want to buy their land? It's hard to say until the villain finally r...