Mark Twain has influenced Karon's writing. The Adventures of Tom Sawyer (1876; see separate entry) and The Adventures of Huckleberry Finn (1884; see separate entry) were two of Karon's favorite books in her youth. Like Twain, Karon emulates authentic regional speech patterns and uses dialogue to develop characterizations. The cave scene is especially reminiscent of Tom Sawyer and Becky Thatcher's adventure when they are lost in a Missouri cave during a school picnic.

Karon says that she went deep into an unexplored limestone cave in Virginia to gain authentic insight into what it is like to be lost underground in the dark.

Father Tim and Cynthia find a different kind of treasure and meet no Injun Joe when they are lost in the cave, but they are confronted with their mortality.

They may never be rescued. Both confess fears that have handicapped their lives.

The treasure they find...