Warning: This article contains spoilers for the Westworld season 3 finale.
One big one is William, a.k.a. the Man in Black (Ed Harris). When last we saw him, he was getting murdered by his android doppelgänger in a post-credits scene. And while his robo-double still seems to be online and kicking, it appears human William is also still around — even after his throat was slit.
Charlotte Hale — er, Dolores 2.0 (Tessa Thompson) — is seen standing before William, who's hooked up to Delos' robot-making machines. "Your kind made a sport out of hunting us," she says, taunting him. "You controlled our every move. And now I'm going to do the same to you." We don't think she would be saying that to a fellow robot, which supports the "William is still alive" theory. But this is Westworld, and nothing is ever as it seems.
HBO Tessa Thompson and Ed Harris on 'Westworld'
"It's time to evolve into the species we were meant to become," Dolores-as-Charlotte adds.
"Maybe it's time you question the nature of your own reality," says William, likely robo-William. "We're not here to transcend. We're here to destroy."
The season 4 trailer begins with another resurrection — one that was already revealed in the previous teaser. Evan Rachel Wood's Dolores, the original Dolores, has somehow been booted back up after the events of season 3. It appears she has no memory of what transpired. She now dresses in suits and goes to an office every day in a futuristic New York, though she talks about a girl in a story that sounds awfully similar to her own experience.
"This is a story about a girl," she begins. "Every single day she wakes up, the more she sees it, but nobody else can. That there's something wrong with the world, and that it's her fault."
Bernard (Jeffrey Wright) is also back with his pal Stubbs (Luke Hemsworth), and Maeve (Thandiwe Newton) and Caleb (Aaron Paul) have teamed up again (going to what could be Delos' 1920s-inspired park). Another Maeve-Dolores face-off appears imminent, and something is going on at this mysterious dam.
Oh, and there are a lot more flies this time around. They've been part of an ongoing motif, but now appear to be a lot more dangerous.
Westworld season 4 premieres Sunday, June 26, at 9 p.m. ET/PT on HBO and HBO Max. Decode the latest trailer above.