Once Grandpa Pecos decided to share a secret with his grandson — there's a hidden treasure buried somewhere on the former mine. But there's one problem. The treasure lies very deep underground at a depth of more than 100 yards! Then the grandson thought about his friend, the Mad Digger. He's the only one to get things done.

Once Grandpa Pecos decided to share a secret with his grandson — there's a hidden treasure buried somewhere on the former mine. But there's one problem. The treasure lies very deep underground at a depth of more than 100 yards! Then the grandson thought about his friend, the Mad Digger. He's the only one to get things done.