Decrypter and the Beale Ciphers

Two hundred years ago, a man hid a fortune and left behind three encrypted letters. No one has cracked them. Until now.When Calla Cress and her closest friend Jack Kleve uncover ancient wall paintings and a hidden telescope deep inside a New Mexico cave, they realise the Beale Ciphers don't lead to gold. They lead to something far more dangerous.Then the cave collapses. Jack vanishes. And Calla is...