Is the new accounts man just a well-dressed young sycophant, or is he a federal agent investigating Don Draper's shady past? Is he Joan's new boyfriend, or is he some sort of undercover investigative reporter?
Now that we're nine episodes into the show's sixth season, a lot of fans have their own theories about this charming, mysterious addition to the cast. In fact, the hashtag #WhoIsBobBenson incited a flurry of responses in response to our initial article.
Check out our favorite fan theories, then let us know your own in the comments section below.