Ok I’ll follow last weeks spectacularly bad guessing, here goes with this one.
1. The Tardis can go into the Nethersphere (Matrix), after all, Missy has appeared in it, presumably using her Tardis.
2. Danny does a ‘Rory’ – dead/undead thing, he changes in the Nethersphere
3. The Cybermen are using Missy as much as she is using them. I think she’ll get turned on by them.
4. The Nethersphere has a clue or clues about Gallifrey within it, but it may have to be destroyed to kill the link to the bodies used by the Cybermen.
5. Osgood seems from the ‘non spoiler’ previews one to watch. I have a theory but it’s very very spoilery.
6. UNIT will be spectacularly bad as usual at handling the alien threat.
7. I’m guessing on a River Song appearance.. (Graveyard/she’s in the ether, time travellers wife book last week)
8. Part of Clara’s ‘mystery’ will be explained, it will be resolved further in the Christmas special.
9. Missy and the Doctor have a common thread in Gallifrey, he does not kill her in this episode, and she may recur in the 2015 Series nine as a foil in the hunt for Gallifrey.
10. I still l think that Clara has objects from the Tardis in her pockets, keys or otherwise that will play a part.
11. Dr Skarosa – yes it’s a Skaros mention, but I’m going to say no Daleks, this episode is a chance to re-establish the Cybermen as proper scary
12. I’ll also go for a former companion appearance. I’d quite enjoy seeing Martha and Mickey.
13. Clara’s speech to the Cyberman saying she’s not Clara Oswald etc, is and isn’t true as there are paradoxes created by her past intersections with the Doctor’s lives. She’s also learned to lie like the Doctor though.
I think there will be some threads tied up in the episode and some left open.