Revenge of Superstition Mountain

The Barker brothers and their good friend Delilah secretly climb up to Superstition Mountain one last time. There are still mysteries to solveis the creepy librarian really the ghost of Julia Thomas from a century before? What was their uncle Hank's role in discovering the gold mine? Can they still get into the gold mine after the avalanche that nearly crushed them? Does their cat, Josie, have mysterious powers? And, most of all, who is trying to kill them?