It was one of my mother’s books from the Book of the Month club. One summer when I was 11 and with nothing to do I began to read some of her adult books instead of the books that children normally read like Walter Farley’s Black Stallion or Terhunes’s books about collies.
It was a revelation in my book reading, and I realized that adults read books that were interesting and exciting. It was made into a damn good movie as well.
Did you ever read the Clair Bee "Chip Hilton" books?
If I can recommend one more..I'm sure you know Alistair MacClean from his epic novels (later films) like "Guns of Navaronne" and "Where Eagles Dare"..but his first novel "HMS Ulysses" is based on his service in WWII..and is, I think, his best work...again..worth trying to find..I think there's an e-book edition