Bubba and Squirt's Big Dig to China by Sherry Ellis

You can’t dig a hole to China!

Squirt doesn’t believe Bubba can dig a hole to China. But when the hole swallows them, the kids find themselves in Xi’an, China, surrounded by Terracotta Warriors.

It gets worse when the ghost of the first emperor of China appears. He tells them they can’t go home until they find his missing pi. The kids don’t know where to begin until they meet a girl and her grandmother who promise to help find the pendant.

Soon they realize they are being followed. And they are no closer to finding the missing pi. Will Bubba and Squirt ever make it back home?