Bill has been changed forever, the Master and Missy are teaming up, and the Doctor will be alone in his final hours — or will he?

The Season 10 finale of Doctor Who, “The Doctor Falls,” teases that it will deliver on just that: showing the rest of the 12th Doctor’s regeneration into a new body that was shown at the start of “World Enough and Time.” But the big finale will also deliver a ton of surprises.

“The Doctor Falls” guest star Samantha Spiro hinted to Radio Times this week, “Nobody is as you think they are — or people aren’t necessarily what they think they are.”

Though as cryptic as any hint, it could mean that Missy or even the Master might not be who or what they seem. At the end of “World Enough and Time,” Missy and the Master were backed by Cybermen and seemingly ready to torment the Doctor. But perhaps one or both of them will have a change of heart(s)?

What sort of dynamic will the three Time Lords have?
What sort of dynamic will the three Time Lords have?

Spiro’s message could also reference Bill’s conversion into a Mondasian Cyberman. Maybe it’s not be quite as final as it seems?

Showrunner did say in a Facebook Live Q&A, regarding Bill, “She’s a Cyberman from now on.” In a joking tone he “confirmed”, “She’s one of those ones in the trailer actually. She was just killing people. That’s the way it is sometimes.” There’s a good chance he’s misleading the audience, so who knows what could really be in store for the companion.

Pearl Mackie, Bill herself, said that the finale will include “quite a lot of endings,” meaning that more than just the tenure of the 12th Doctor will come to an end. Will it spell the end of the Master and Bill as well?

If recent trailers are any indication, then Missy’s return to evil and teaming up with the Master might not be permanent; the Doctor pleads, “Stand with me! That’s all I’ve ever wanted.” She will at the very least waver in her commitment to evil, and at some point, all three Time Lords will point their sonic devices in the same direction. Will they be comrades in arms at last?

“The Doctor Falls” will air Saturday on BBC and BBC America at 9 p.m. Eastern.

Photos via 'Doctor Who'