I thought Eddie Willers had a few conversations with Galt early on in the book although Willers and the reader didnt find out that it was Galt until late in the book.
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I don’t think we’re ever told for sure in the book that Eddie’s friend was Galt, but I always believed it was.
When Eddie hears John Galt give The Speech on the radio, he recognizes the voice as belonging to his friend, the Anonymous Rail Worker.