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Near the end of Fantastic Beasts and Where to Find Them, Newt casts

revelio, showing that the Graves we see is really Gellert Grindelwald. As far as I am aware, the movie until this point had not provided any "tells" that Grindelwald had been impersonating Graves.

Thus, why did Newt cast this spell?

marked as duplicate by Valorum, Community Dec 4 '16 at 13:15

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