Last night the penultimate episode of series five of Doctor Who, with new Doctor Matthew Smith. If you’re watching the series and you’re not up to episode 12, please be warned there will be many, many spoilers from this point. Big honkin’ spoilers, sometimes about the lack of ducks.

I’ve really enjoyed the season so far. Matthew Smith’s doctor is odd and funny, and always fun to watch. Karen Gillan as Amy Pond is easily one of favorite companions ever, gorgeous and vivacious. The chemistry between the two is perfect.

“The Pandorica Opens” acts as a capstone for the current series. From the pre-credits sequence where we follow a lost Van Gogh painting travel though the hands of several characters who we’ve seen this season to the “alliance” of every alien race who hates the Doctor, there’s a lot to reward someone who’s watched the entire series. There are even some shout-outs to old school continuity, with the Draconians, Terileptils, Zygons and Drahvins being mentioned among the alien races coming to capture the Pandorica. By the time the first part of the two-part finale ends the most obvious question has been answered (the Pandorica is opened and we find out there’s nothing inside) and we’ve seen a collection of every alien costume the BBC still had lying around, yet we are left with so many more questions. Time for speculation! Speculation that look completely idiotic a week from now when “The Big Bang” airs! But we speculate anyway! Everything that follows is the result of either my own silly ideas or ones that were gleaned from discussions with my friends Joel and Jyo.

Despite the alliance of rubber costumes locking the Doctor in the Pandorica there seems to be an as yet unseen Big Bad truly responsible for the TARDIS’s destruction. At minimum the Big Bad appears to have hijacked the TARDIS when River tried to pilot it to Stonehenge, made it land at Amy’s house next Saturday, and in some fashion arranged for it to blow up, thereby causing the destruction of the entire universe. When the TARDIS lands at the fatal location we hear a voice say “Silence will fall!” Who is this Big Bad? We don’t have much to go on, but I’ll list a few possibilities, and the arguments pro and con for each one.

- Davros. The voice that says “Silence will fall!” sounds a bit like Davros. In “The Stolen Earth” Davros had developed technology that could destroy the entire universe. But would he? Davros wanted to destroy the entire universe except the Daleks, and he couldn’t control a TARDIS remotely.

- Rassilon. Seems a little early to have Rassilon back, and the voice wasn’t Timothy Dalton. Rassilon is probably crazy enough to destroy the universe, and he could control the TARDIS, so he’s got to be considered a possibility.

- Omega. Another Timelord, this one quite insane and trapped in the anti-matter universe. He certainly could do everything the Big Bad has done, but he hasn’t been mentioned in the new series.

- The Celestial Toymaker, my personal favorite candidate. He’s a villain who appeared in a single story back in 1966, though the Doctor recognized the Toymaker at the beginning of the story, and at the end of the story the Doctor was oddly adamant that he would have to face the Toymaker again. The Toymaker was insane and capable of creating his own universe, so destroying the current universe wouldn’t be out of the question. He was certainly capable of hijacking the TARDIS. I don’t know why he would want silence in particular, but I could argue there was a game-like quality to the Stonehenge trap. He would be an obscure villain to resurrect, especially since three of the four episodes he’s appeared in are lost.

- The Black Guardian. Supremely powerful, evil, and has a history of using ginger-headed companions against the Doctor. Also wears a bird on his head.

- Satan from “The Satan Pit.” He’s probably pretty pissed about being dropped in a black hole.

- The Doctor himself. This is the favorite theory of Joel and Jyo. The idea here is that the Doctor spends millennia inside the Pandorica and when he comes out he’s a lot less nice than he used to be. There have been some hints this season about the Doctor’s darkness, particularly in “Amy’s Choice.” I don’t really buy this one. I think the Doctor will escape the Pandorica immediately.

How will the Doctor escape the Pandorica? At the beginning of “The Pandorica Opens” River Song acquires a vortex manipulator “off the wrist of a handsome Time Agent.” A vortex manipulator is the time travel device of choice of Time Agents Captain Jack Harkness and Captain John Hart, so the it could be from either of them. Later in the episode we see the vortex manipulator sitting on the Pandorica dais as the Doctor is working, and finally we see the Doctor slip something in his pocket when he’s talking to Rory. The Doctor used the same trick to escape the Futurekind at the end of “Utopia,” but I suppose if something works once it can work again.

With the Doctor free to travel in time without the TARDIS we’ll no doubt see him go back to some previous episodes and start meddling. A second Doctor can be seen in Amelia’s house in “The Eleventh Hour” when Amelia goes outside to wait for the TARDIS to return, and it was almost certainly a second Doctor who told Amy to “remember what I told you when you were seven” when she was forced to keep her eyes closed in the forest on the Byzantium. (The tell is that the Doctor is wearing his coat, which he lost several scenes earlier.) There is no obvious thing that the Doctor said to Amelia that the older Amy would need to remember, so presumably the Doctor tells it to Amelia after his earlier self has already left her. Timey-wimey, indeed.

The other big mystery is why, as the Doctor observes, Amy’s life doesn’t make any sense. The Doctor reveals that the real reason he took Amy with him was because he noticed that it didn’t make sense that she lived in such a large house by herself. The implications now is that Amy used to live with a much larger family, but they all got eaten by the crack and therefore “never existed” is the same way as Rory. Of course, this version of “never existed” is a not exactly ironclad or complete. Rory still appears in photos and left the ring behind, and if Amy’s father was consumed by the crack then Amy shouldn’t exist either. I assume that Amy’s mother died before the crack because Amelia definitely remembers her and her produce presentation skills. Or perhaps the large family Amelia was living with was directly related to her aunt by marriage, and Amelia had been orphaned years before. I suspect one way or another we’ll find out on Saturday.

Another possibility, albeit an unlikely one, is that Amy Pond is not a real person. Perhaps she is an Auton, or some other creation of the Big Bad. Following this through, perhaps all of Leadworth is fake, which the Doctor subconsciously noticed when he demanded to know how Amy knew it was a duck pond if there were no ducks. The fake Amy/Leadworth theory would explain why Amy didn’t know about Daleks or Cybermen.

Now for the lightning round. Each of these is just a quick question.

What were those strange burns on the lawn in front of Amy’s house when River arrives there? From the shape they could be Daleks landing. The shape is closer to the Bling Daleks of seasons 1 – 4, as opposed to the new, rounder Candy Daleks. Or perhaps those shapes were left by the Big Bad?

Who is River to the Doctor? Theories have been all over the place, from the Doctor’s future wife, to his mother, to the Rani, to Romana, to a future Doctor. At the end of The Pandorica opens she does call the Doctor “my love,” so I guess “wife” is now the frontrunner.

Why do the alliance aliens think only the Doctor can pilot the TARDIS? Obviously that isn’t true, as several other people have piloted the TARDIS, and two other just this season. Is that just a mistake on their part, or did the Big Bad lie to them to get them to go along with his plan?

Why did River Song tell the Doctor to meet her in Roman Britain near Stonehenge, which just happened to be where the Pandorica was? I suspect that this plot hole probably has an explanation that was cut for time, like that the coordinates were also part of Van Gogh’s painting, or that River had independently located the Pandorica to that general area.

Who did River kill to be put in the Stormcage Containment Facility? “The Pandorica Opens” starts with her there, so that’s a story we’ll have to wait for.

Who lost their arm? Jack Harkness or John Hart?

Who are all those spaceships? Daleks, Sontarans, Judoon and Atraxi are easy enough to spot. There is another very prominent ship seen in many shots, but I’m pretty sure it’s not one we’ve seen before. There’s also a gold-ish organic sphere that I like to think is the Zygons.

That’s it. Now all that’s left is the waiting. The tortuous waiting.