Since the very first season of Westworld, fans have speculated that there's more to the Man in Black than there seems. The mystery appeared to be solved when the villainous character played by Ed Harris was revealed to be the older version of archetypical Nice Guy William. What other secrets could he possibly be hiding after one that big? Well, "Vanishing Point" raised yet another interesting question: is the Man in Black a host on Westworld?
This isn't a new theory. Many noted similarities between William and a character played by Yul Brynner in the 1973 film upon which the show is based. Brynner's character was a robot who went rogue and started attacking guests in the park; though he shared more traits with Dolores, he was visibly very reminiscent of the Man in Black. They even had a similar costume.
But throughout the first season, it felt like William was definitely human rather than host: he was impervious to bullets until the finale and he was too high up the ladder in the Delos Corporation to be a host in disguise. However, Season 2 has blurred all the lines, especially for William. It's not clear if he's actually an android or if too much time spent in Westworld has warped his perception of reality.
It seemed a little suspicious in "Phase Space" when William was riddled with bullets in a shoot-out but didn't die. He was weakened, sure, but he lingered all throughout that episode and the next with minimal care; despite his many injuries, he miraculously didn't bleed out. In "Vanishing Point" he was even able to stand up, walk around, and steal a gun to stage another shoot-out of his own. Only hosts have been shown to withstand that much damage and keep moving, because mortality is not a concern for them.
In the final half of the episode, there were hints that something strange might be going on with William. He touched a spot on his arm that is significant to hosts: the inside of the right forearm, which is the location of the plug that techs use to access hosts' data. He was also paranoid, accusing his daughter of being a host planted by Ford and even going so far as to kill her before he realized she was human after all. After that, he seemed to be hearing the voice of his late wife as he dug a knife point into that spot on his forearm, perhaps hoping to find out the true nature of his reality. But the episode ended before the audience could be clued in, too.
Revealing that a character previously assumed to be human is really a host is the kind of thing that has diminishing returns. Westworld already did it to great effect in Season 1 with Bernard, and to some extent played the trick again with James Delos in Season 2. James had been human, but the company was experimenting with placing his consciousness into a host body; there's a chance the same thing was done with William, and James was simply foreshadowing for William realizing that he had been replaced with a host version of himself at some point.
Anything is possible on Westworld. It's totally plausible that William is a host and there's enough evidence to support it if you dig. But it might not have the same impact since viewers have seen that story play out before. Fans will have to wait until the finale to figure out what exactly is going on with William, though whatever it is will surely have lasting ramifications for the series.