This silly early-reader tale of a frog scientist and his niece and nephew frog apprentices is full of fact and fiction. There is some interesting science as they tunnel in their supernaturally heat-proof tunneling machine and explore the layers of the earth. Along the way, frog nephew Tad pushes the ACH (Anything Can Happen) button, which explains some of the silly fiction they encounter along the way: dinosaur fossils that come to life and attack their tunneling machine, a yeti monster making silly faces at the top of Mt. Everest, cave-man frogs who have drawn pictures on cave walls, and of course the heat-proof machine that can manage thousands of degrees until it melts at the very core.

If those fantastic creatures don’t bother you, the only other thing that might be an issue for some families is references to ages of the dinosaurs that are in the 28-million-years-ago type range.

As for me, the stuff I learned about the crazy design of our amazing earth (and the lack of gravity at the center!) made this sci-fi tale well worth it. Future geology majors will eat this up!