Tonight's episode of Westworld confirmed several popular theories about the show, including the identity of the mysterious Arnold. Previous episodes of Westworld established that Arnold was Ford's original partner and helped Ford build and program the park's earliest hosts. Arnold wanted to do more than just create human facsimiles, he wanted to actually create self-sentient life.
At some point in the park's past, Arnold died in an "accident" involving Dolores and the Man in Black. However, recent events in the park suggested that Arnold was still somehow influencing the hosts and pushing the hosts towards self-sentience. While it's still unclear who is tampering with the host's programming, tonight's episode revealed that another aspect of Arnold lived on via Bernard, Ford's right hand man/secret host.
It turns out that Ford created Bernard in Arnold's image and even programmed Bernard to mimic Arnold's mannerisms. While it's a bit creepy that Ford would create a host to look like his dead friend, Arnold has also created hosts to look like and act like "real" people...namely Ford's robot family that now lives in secret in a remote part of the park.
Bernard "being" Arnold helps explains several of the show's more confusing scenes. While Westworld led us to believe that Dolores was meeting Bernard in secret in the present day, tonight's episode revealed that Dolores was actually meeting Arnold in a secret workshop underneath a church inside Escalante, the first town built inside Westworld. What's more, those meetings with Dolores may have something to do with The Maze, a mysterious path that hosts follow when they become sentient for the first time.
There were several clues that Bernard had some secret connection to Arnold. When Bernard first talked to Ford about Arnold, Ford handed him a picture that supposedly showed Ford standing next to his old partner. Bernard only saw two people in the photo: a young Ford and an older man that turned out to be a host built by Arnold. However, there was a large blank spot in the photo that many fans theorized contained a third person. Tonight's episode confirmed that Bernard couldn't see Arnold in the photo, as Bernard can't see things that would cause him to realize he was a host.
So what does this mean for Westworld? Well, if Bernard was modeled after Arnold's image and given his mannerisms, it's possible that Bernard was also somehow the person tampering with the host's programming. As the head of the Behavior department, Bernard would certainly have the means and ability to reprogram hosts at will, although it's unclear how he would keep it a secret from Ford. Since Ford forced Bernard to kill himself at the end of tonight's episode, we'll have to see if Bernard's connection to Arnold has any greater meaning....or if it's just a way to keep actor Jeffrey Wright involved with the show via flashbacks.