Why were people warned to not go on Superstition Mountain? Was there really a lost gold mine there? Whose skulls were lined up on the ledge? Simon, Henry, and Jack couldn’t pass up the temptation to explore and had a very exciting adventure. Looking for historical information in the library introduced them to a new neighbor, Delilah, who also wanted to explore. Unfortunately, she had an accident on the mountain, which led to finding a hidden canyon and another mystery. This was an exciting book that was hard to put down (even as an aging adult).