It's totally clear, see the paragraph starting "It’s at this point in the story that"
What specifically did Wolfe discover? Certainly not the Brooke-Dethick feud itself: https://books.google.com/books?id=EAuvCFM2S34C&pg=PA183&lpg=.... Perhaps new information about it? Surely the Guardian's readers could handle a detail or two. It's after all customary for an article about a new discovery to say what the discovery is.