If you’re an American history buff, you’ll want to check out this video from the National Archives, which details historians’ efforts to try and figure out what President Richard Nixon and his chief of staff H.R. “Bob” Haldeman were talking about during an 18 1/2-minute gap in a recording made shortly after five men were arrested for breaking into the Watergate complex in 1972. Who knows? Maybe they were talking about the trees. [via Mother Jones.]