Westworld Seasons 2 and 3 both ended with shocking post-credit sequences. Season 2's finale revealed, far in the future, William, aka The Man In Black (Ed Harris), had become a host. Despite the collapse of Delos and the park, he was still wandering around, being tested for "fidelity" by a host version of his dead daughter, Emily. Season 3 did one better and revealed how the real William died, assassinated by his own host copy, a pure version of his Man in Black persona. Now, these Westworld Season 4 details suggest how Season 3's ending will eventually lead to the future fans saw at the end of Season 2.
William's death was inevitable in Season 3, once an extended therapy session left him convinced the only way he could be a hero was to kill all the hosts. The series is told from the hosts' perspective; they are the protagonists. William was a villain because he owned the hosts and treated them like his property. But once he became convinced he needed to destroy the whole lot of them, it was only a matter of time before someone — Dolores, Maeve, Charlotte, Bernard — removed the threat.
In the end, Charlotte (Tessa Thompson) did the honors. She created a new William to murder the real one and replace him. Her "Man In Black" was a distillation of all William's ugly and violent tendencies, but now working to advance the hosts' interest. That puts two hosts at the head of Delos' decision making: William, the main shareholder, and Charlotte as his executive director.
According to showrunner Jonathan Nolan, that's going to prove a terrifying combination come next season.
Speaking to Entertainment Weekly, Nolan said:
I'm a big believer in being guided by irony. [William] winds up becoming this thing [a host] that he’s controlled for so long. And on a visceral level, I just can’t wait to watch Ed kill everyone.
I was happy to get back in my black suit. I have no idea what they have planned for me. I'm teamed with Tessa, I know. Hopefully, we can do some rightful damage.
Fans can't wait to see how much havoc these two wreak next season. Westworld Season 4 is expected to arrive in 2022.