Downton Abbey season six, the final season, premiered in the U.S. yesterday to great acclaim. It wouldn’t look the way it does or be so historically accurate, however, if it weren’t for Alastair Bruce. The cast and crew of Downton Abbey, Masterpiece’s smash hit about the Crawley family and their servants call Bruce, the show’s historical advisor, “The Oracle” because he knows everything about the customs and protocols of the time period.