Variety compared the colorized, 3D footage in They Will Not Grow Old to the moment in The Wizard of Oz when Dorothy steps out of her sepia-toned world into lavishing Technicolor. “If this sounds like the world’s most state-of-the-art educational video, that’s exactly what it is,” Guy Lodge wrote for Variety. In the Guardian, Peter Bradshaw calls it a “visually staggering thought experiment,” adding that “the soldiers are returned to an eerie, hyperreal kind of life in front of our eyes, like ghosts or figures summoned up in a seance.”

Such dramatic technical changes could have easily felt like a gimmick, but it sounds as though Jackson avoided that pitfall, instead using the restorations to bring an immediacy to a war that until now has only been seen in grainy black-and-white footage. According to reviewers, the film is unsparing in its depiction of the trenches, showing in detail the horrid realities of the day.

Those realities were experienced by Tolkien himself as a 24-year-old British soldier at the Battle of the Somme in 1916. It was in the trenches where the author first came up with some of the ideas for his fantasy world, which Jackson would adapt for film 85 years later.

In the UK, the BBC will broadcast They Will Not Grow Old on Armistice Day, Nov. 11—exactly 100 years from the end of the war. We’ll update this story when international release dates are announced.

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