The Doctor's big honeymoon treat for Rory and Amy lasts about ten seconds before, of course, everything goes to hell. Their pleasure barge goes shooting into the atmosphere of a very complicated planet run by a miserly old Scrooge with a history chock full of child abuse and a present chock full of everybody abuse. There's some sort of snow-cloud-fog action happening that contains lots of pretty fish and one very angry momma-shark -- and also apparently crashes ships.
So Scrooge is mean to everybody for awhile and plans on letting the people on Amy's ship die for no real reason, but then the Doctor makes the ethically dubious choice of traveling back to his childhood and going full Mrs. Doubtfire on the kid in the hopes that he can change his entire life around and make him a nice guy. Kind of like killing Baby Hitler, but with niceness. Also pretty much a total violation, but whatever.
Baby Scrooge is fixated on this pretty frozen lady -- the family Scrooge keeps frozen people in coffins as loan collateral -- who loves the space fishes, like he does, and also sings beautiful songs to the shark. Maybe she does other things, or has some kind of personality, but this is Moffatt we're talking about so mostly she's just dewy and sings songs and is dying of some mystery disease. The Doctor and Kid Scrooge take her out of her box every Christmas to play with her and then put her back when they're done.
Sadly, not even the Doctor knows that there are only like eight plays in the lady before she dies forever. By the time Scrooge has become a hot young fellow, she decides to tell him about her mysterious disease. Instead of telling the Doctor and getting help, he ends up shutting down emotionally in all kinds of ways, meaning that in the present Amy and Rory are still going to die. Amy and Rory take over brainwashing Scrooge for a second so Amy can get the story on the dying lady, and then the Doctor brings Baby Scrooge to Old Scrooge so they can have some sort of emotional catharsis.
None of which has solved the problem, because now Scrooge is too nice to operate the cloud-snow machine (don't ask), but luckily the shark swallowed half of his screwdriver, which is sonic if you'll recall, and so they bring the lady out of cold storage one more time, so she can sing to the clouds, via the shark, and then go on a shark ride, and then die. All of which takes about a half hour, during which she is singing the entire time.
It's very touching, all told -- even with the classic Moffatt hallmarks of making no actual sense, bold-faced emotional manipulation, thirty thousand things that have no business being in a story together, and the nonstop parade of completely soulless female characters -- and props must be given for not going to the million hackneyed places a "Christmas Carol" redux might go, especially given this past season. All in all, a really very moving tale -- owing more to Pinocchio than Dickens, really -- especially with Matt Smith doing even more of the heavy lifting than usual.
More distracting lens flare than you can shake an Enterprise at, and the stormgate is critical as a pleasure barge crew runs around shouting on the bridge: They're heading into a very intense atmosphere and there's no response from the surface. Amy and her husband what's his face, Rory, come running out having summoned the Doctor to save them, and of course they are wearing policewoman and Centurion outfits, because of course people in their twenties are so bad at sex that they require kinky outfits. (On the other hand, if you ever wondered whether the policewoman outfit was exactly what it seemed to be, now you know. Both inside and outside the show.) Very dangerous, lots of science fiction yelling and more lens flare, and they're heading into orbit, and then there's the TARDIS, coming up alongside: It's Christmas.
Down on the planet a sour Mr. Sardick is giving a speech about Christmas, like so: "On every world, wherever people are, in the deepest part of the winter, at the exact midpoint... Everybody stops and turns and hugs. As if to say Well done. Well done, everyone. We're halfway out of the dark. Back on Earth, we called this Christmas. Or the Winter Solstice. On this world, the first settlers called it the Crystal Feast."
Hugs. Isn't that just jolly? But here on the planet of the fish-fog, Sardick calls it expecting something for nothing. He is not one for "hugs," no sir. He is one for meanness and yelling at poor people. I certainly hope somebody comes along and teaches him the meaning of Christmas by showing him his past, present and future. That would be original.
The Cratchits in question are there to see a beautiful lady who is apparently frozen in a coffin with only her face exposed. They'd like him to let her out so she can enjoy Christmas -- her favorite holiday -- but since nobody has reprogrammed his brain yet, he doesn't care a whole lot. In fact, he jokes about it incessantly. Sometimes he'll make a pun that's not that funny and then turn to his employees and say, "That was funny," and they'll laugh. He's a very unique character. So the situation is that on this planet, where he lives now even though he once apparently lived on Earth -- not that we'll ever get back to that -- he is in charge of things like the sky and the fog-fish and also loaning people money. In return, he takes their loved ones and puts them in frozen caskets for a while. Doesn't that sound likely?
Turns out this family has had this young lady in cold storage for a good long while, in fact: Her sister is now more the age of her mother. I don't know about you, but if my family left me in there that long I would have something to say about it. That's because I have a personality, though, so no worries here. One of the employees keeps trying to tell Scrooge that there's a spaceship about to crash into the planet, but he doesn't really care. He thinks it will be funny if they die. And he hasn't even met Rory yet!