Recently the Squirrel Boy and I have been re-reading the Great Illustrated Classics version of Jules Verne's A Journey to the Center of the Earth. We read one or two chapters a night before bedtime, and so far it's the only one of this series he's wanted to read twice (we've done Treasure Island, Twenty Thousand Leagues Under the Sea, Moby Dick, Tom Sawyer and Oliver Twist). Something about this tale of original extreme spelunking apparently struck a chord for him.
Perhaps it was our adventures at the Cave of the Mounds. When we were halfway through our first reading, I mentioned that if he wanted, we could visit an actual cave just like the ones in the book. Apparently taking account of the nature of our heroes' adventure, he looked at me very seriously and said, "You do know we could die, don't you?"
Nevertheless, we did visit the cave and had a wonderful time.
And now we're re-reading the novel, which I don't mind at all.