Doctor Who is not a series known for good titles. The classic series is full of stories called things like “The Robots of Death,” “The Seeds of Doom,” and “Terror of the Autons,” to the point that its most successful parody (written by Steven Moffat himself) was called “The Curse of the Fatal Death.”

“Let’s Kill Hitler” is a brilliant title, for two reasons. One is that it’s almost as far from those old-school corny titles as possible. The other is that it might be the biggest mislead in the history of the series.

I hope you’ve already watched it, so I don’t spoil it by saying this story drops any pretense of being about Hitler at the 17-minute mark. It’s a good thing, too; there’s something a little awkward about using Hitler as a comical red herring, made even more awkward by the fact that our heroes are required both to look appropriately appalled by their encounter with the dictator and also to lock him in a closet like a Scooby-Doo villain.

Ultimately, Hitler is a fairly arbitrary means of not only misdirecting us but also bringing in the Tesselator, a really entertaining concept: a person-sized, chameleonic space/time ship containing miniaturized future cops tasked with hunting down war criminals from the past, plucking them from time just before their historical deaths or disappearances, and punishing them through torture (“giving them hell,” as they themselves put it).

It’s fun to watch them drive the body and update its disguises in their ninja mission to reach Hitler himself (their intended target), and perplexing to wonder why they waited until the very last minute to check their chronometers and discover they’ve arrived seven years too early and aren’t allowed to torture Hitler yet. It’s also weird that they’ve got all this technology but a really precarious security system of “antibodies,” but maybe that’s part of the episode’s theme about the fine line between damned and pardonable.

Some viewers will probably be tempted to damn Steven Moffat for Mels. I’m inclined to forgive him, but for 17 minutes I was thinking: okay, so Amy and Rory had a best friend from childhood we’ve never heard about before now, someone they played Doctor with (not like that), someone who watched them fall for each other (after Amy discovers he wasn’t gay, as she’d always assumed), someone whom Amy almost certainly would have told when the Doctor finally came back for her and who would have wanted to meet him right away. Oh, and she acts just like a young version of River Song, trigger-happy, thrill-seeking, and Doctor-lusting. Could this possibly be any more contrived?

Then (I really hope you’ve already watched it) we find out Mels is short for Melody, and that she acts like a young version of River Song because she is a young version of River Song. And presumably she’s been biding her time since she regenerated in that New York alley in the early 70s, tracking down and then growing up alongside her future mom and dad, waiting until the two of them travel with the Doctor, have a TARDIS baby, and ultimately lose her to Eyepatch Lady to be trained to assassinate the Doctor.

So, yes, it could be and is more contrived, but maybe it also couldn’t have worked any other way.

The Doctor turns out to be easy to kill, but hard to watch die, which I guess is a pretty good defense mechanism. It’s never really explained why he can’t regenerate his way out of it. Presumably this is one of the many quirks of Judas Tree poison, along with being painful but tolerable until the final moments, and being harmless to Melody herself.

The high stakes almost, but not quite, distract from Alex Kingston’s unsettling acting when she’s being “given hell” and from the ruthless way Amy is willing to skip diplomacy and murder everyone on the Tesselator to stop this from happening (like mother, like daughter).

Perhaps more than any other Moffat script, this one is split between clever and melodramatic, and there’s not a lot of time for Amy and Rory to convincingly register the surely-mind-blowing situations they’re in: they’ve had a daughter, lost her, then realize they’ve grown up with her, and that she’s an assassin trained to kill the man they’ve trusted with their lives, and that they’ve narrowly saved both from certain death in the space of about a half hour.

Generally they react not as they would, but as we do: as though this were a story they’re living in, and they’re impatient to get to the next chapter to see what happens to the characters they’ve come to care for.

Kingston’s acting is just fine, but it feels as though even she’s a little uncertain how to play herself as a self-described psychopath who is yet somehow moved by the Doctor’s compassion and has a change of heart. It’s confusing because we know River pretty well now, and it’s hard to be really scared by her or find her epiphany surprising. That’s the real problem with spoilers: a story driven by heart will always survive them, but a story driven by surprise won’t.

Which is not to say I didn’t thoroughly enjoy it, even the second time. There’s plenty of heart, naked and exposed, but you have to look for it in the smaller moments, like the scene where the Doctor is trying to choose an appearance for the TARDIS voice interface. The ship’s first choice is an image of the Doctor himself and he protests, “Get me someone I like.” Then it’s Rose, Martha, and Donna: “guilt,” “guilt,” and “more guilt.” Finally he gets young Amelia Pond, “before I got it all wrong.”

Some might call it emo, but Matt Smith puts the -tion on it and it works, heartbreakingly. For all the brain-melting revelations about River (and we’re not done, because apparently we still haven’t seen the crime she’s in prison for), this might be the key scene of the episode.

Then there are the one-liners:

• Rory, inside the Tesselator while it’s mimicking Amy: “I’m trapped inside a giant robot replica of my wife. I’m really trying not to see this as a metaphor.”
• "Melody, inspecting her newly regenerated body and explaining why Alex Kingston looks youngest at the end of River’s life: “I might take the age down gradually. Just to freak people out.”
• The time cops, wondering whether the Doctor is really supposed to die now: “Time can be rewritten. Remember Kennedy?”
• The Doctor, working the title in as a meta-joke one more time: “Doctor Who?”

And, of course, the open questions:

• Turns out the Silence are a religious order obsessed with some ultimate universal Question. Will we ever learn what it is, or is this a Hitchhiker’s Guide in-joke?
• Why do so many people regenerate standing up in the new series? It can’t be comfortable.
• How big of a nerd am I for wishing Moffat had written “transmat” (the Who term) instead of “beamup” (the Trek term)?
• Who IS “Benjamin”? Did I miss it?
• Is it my imagination, or does Karen Gillan look foxier and foxier as the series goes on?