I just finished The Oracle: The lost secrets and hidden message of ancient Delphi by William J Broad. This is a nonfiction work that is less about what the oracle did and said and more about how modern times have viewed the oracle.
I don't have much interest in geology, slightly more in archaeology. Yet this book was a really interesting read. It tells the story of a group of men and their quest to prove (by geology) that the oracle was not a total fraud. It all comes down to hydrocarbon vapors rising out of faults in the earth.
Through it all, Broad emphasizes that at any given time, science does NOT know everything. What seems certain now can be proven totally wrong later.
After all, the sun does not revolve around a flat earth.