|Don't be too literal|
One of my favorite authors is Loren Estleman, and he wrote a book called Sudden Country that is an old west/frontier version of Robert Louis Stevenson's Treasure Island set in Dakota Territory. It took me a few chapters to catch on to what he was doing, but I really enjoyed it after that, seeing how he was going to work it out in a new setting.
This is something I have plans to do - and indeed did do with one of my books, but you have to look close to find it! I have ideas for books such as the Mel Gibson film Payback (its self a remake of an earlier James Coburn movie called Point Blank) set in the wild west, or the Dashiell Hammett classic Red Harvest re-imagined as a fantasy.
This kind of thing can be very interesting and fun. Red Harvest alone has been remade a half dozen times in various settings (Yojimbo - Feudal Japan, A Fist Full Of Dollars - old west, Last Man Standing - 30's gangsters, etc). O Brother Where Art Thou is a re-imagining of Homer's Odyssey. It happens less often in books, as authors are very prickly about their work being rewritten and readers as well as critics are very critical of such an effort, but it happens. Estleman's wife was concerned that Sudden Country was too literal a re-imagining, and almost a rip off.
And that's the concern. Because the line between homage and just flat plagiarism or ripping an author off is pretty fine. Doing your reimagining of the Narnia books can very easily get you into copyright problems, and you run the danger of angering plenty of fans. And finding that line where you are coming up with something new instead of just fan fiction or rebooting a book can be difficult.
If you do a scene-for-scene copy of an existing book, that's too literal and direct. Nobody will take it seriously unless they've never heard of the book and then they might think you're brilliant. Even a more broad re-imagining is difficult, as true fans may become very upset at what you've done.
Say you like the film Captain Phillips and decide you'd like to write a book based on that, but set it in the 1600s on the Spanish Main. That's going to fit in well, pirates and all, but if you just depict exactly the same events in the same order with slightly different clothing and technology, you've not written an homate or a re-imaginging, you've just ripped off the original book.
But if you change main characters, shift the perspective of the book, jumble events around somewhat, and add in other minor subplots, you have a different, but related story. The key is breaking down the story you want to write to its most basic skeleton: merchant ship captured by pirates, captain uses tricks to delay the pirates, and the ship is rescued.
With that skeleton you can start to build on the story. In the 1600s nobody has a radio, so he could use the flag signalling system to pretend to be talking to ships over the horizon from the pirates' perspective (this actually was used and worked in the age of sail several times). Instead of being captured and taken to shore, the pirates could capture the ship and try to sail it to a nearby island for looting and pillaging. Instead of being the SEALs who rescue the ship, perhaps its a shipwrecked English warship crew and captain on the other side of the island that contacts the merchant ship, and so on.
Other minor subplots can be added; what if the crew slipped some expensive personal items for sale at the port of call into the hold and the captain didn't know; the crewmen might be irrational and stupid to protect their money. What if the captain doesn't have the confidence of his crew and has to earn their trust. What if a storm hits, on and on. Adding these kind of details and shifting others turns the basic skeleton of the story into a new one, while retaining aspects of what you liked in the basic story.
|In space no one can hear your accent|
The question must be asked though: is this a valid thing to do? Are you less of an author for taking other plots and sketches, then adapting them to your own story instead of coming up with your own? To a certain extent, there's nothing new under the sun. Nobody, anywhere, is coming up with a totally fresh new story that hasn't been done before by the millions who came before over the eons of human storytelling. Your brilliant inspiration was already used by some guy telling stories around a campfire 3000 years ago. And that's fine.
Because its what you do with a story that makes it matter, the idea is just that: an idea. Your writing skills and perspective, your "voice" and the world you create will make that idea into a story that is yours alone.
So using an existing sketch or idea (I want to write a fantasy version of Gone With The Wind! I have an idea for a Sci Fi High Noon - wait, that's been done with Outland) to create a new novel is not as crass or silly as it might seem. To a certain extent all of us are derivative of what we've read, seen, and heard before. What we write is an extension of our consciousness, memories, education, and experiences and that necessarily includes books and stories we've heard before.
Its just a matter of making it yours instead of simply repackaging it slightly and putting your name on it. Once you've turned the story into your own, you can proudly say you have actually written a book, not vaguely changed some details with a new cover.