Oscar-winning film editor Lee Smith likes puzzles. And it shows. The guy responsible for piecing together timeline-shifting head-scratchers like Inception, Dunkirk, and Interstellar has a knack for crafting complex narratives in ways that make sense, and while it may come as an initial surprise that he’s who director Sam Mendes called to edit his one-shot movie 1917—which is out on Digital HD starting today—once you hear what went into actually putting 1917 together editorially, you’ll understand why he was the perfect man for the job. 1917 presents a World War I-set …

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