In all three tellings, Joey's run ends in the hellish desolation of no man's land. He's trapped in the tangle of barbed wire separating the Germans and the English, who stop fighting when they see him.
"I see it as a story about, you know, the connections that an animal can make - that perhaps only an animal can make - in bringing people together and bringing everybody on the same side of an issue, even an issue as large as the great war, the first World War," Spielberg said. "And sometimes it takes something as, I guess, primal, as a magnificent horse to let everybody share a common goal, which is this: Rescue it.
"And I think that's where the story came down emotionally for me."
A story that's taken on a life of its own. Michael Morpurgo's novel begins in the old school they use now for the village hall. Below the clock that has stood always at one minute past ten hangs a small dusty painting of a horse, Joey. Tourists flocked to see it, but of course, it didn't exist.
"The problem is that they go to the lady who's a dear friend of mine who lives next door to the village hall and they knock on her door and they say, 'Could we see the picture?' And she said, 'Well, it's gone out to be cleaned' or 'It's in a museum' - all sorts of fibs she was telling!" said Morpurgo.
While on location with Spielberg, Morpurgo and his wife commissioned an artist working on the film to paint one.
So now below the clock there really is a painting of Joey - a fictional horse, with truth to tell.
WEB EXTRA: An extended interview with Michael Morpurgo on horses' military service and the genesis of his story.
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