There is an important secret that has been hidden in Mexico for more that 1,000 years. Kris and Jeff Ford and their two best friends, Many and Ken, want to find out about this secret. But other people want to know about the secret, also, because it might be worth a lot of money. The secret is hidden deep in the jungle. If the kids want to find it, they will have to get past snakes and deadly poison. They will also have to get past a man named Hector. Hector will do anything for money. Nick Ford can't come to Mexico to help the kids, because he's on a job in San Francisco. But Nick won't have to find the secret of old Mexico. It will come and find him!