Everyone's favorite Time Lord returned to our screens last night as Doctor Who's sixth season came back for its second half with a belter of an opener. But just because it was amazing didn't mean that we don't have five questions to ask... Okay, maybe more than five...

Okay, I don't want to go completely fanboyish on you or anything, but... That was a really, really good episode for the series to return with, managing to advance the longrunning plots while also paying off all manner of things (The questions we got answered! The weird-but-welcome reveal that Amy and Rory had "raised" their daughter after all! A surprisingly quick end to the search for Melody!) and still offering a fun romp in and of itself (Am I the only one who thought that Rory was just great this week? Punching Hitler! Yes!). Maybe I've just missed this show more than I thought, but I loved "Let's Kill Hitler" a lot - and not least of all because the sensationalistic title both managed to have some payoff and still work as the ultimate red herring. I mean, did anyone really think that Mels was going to turn out to regenerate into River? Which leads me to...

How Much Did Melody/Mels/River Know About Her Past?

So, Mels had apparently searched out her parents after regenerating at the end of "Day of The Moon" - which suggests that she knew something about Amy and Rory, but clearly not everything, otherwise she would know that the Doctor was "worth it." But did Mels/Melody know that she was a Time Lord? She knew that she could regenerate, obviously, but apparently, she also knew how to control her age - She mentioned wanting to age in reverse very slowly, after all - which implies that she knows her capabilities more than we might expect. Just what was Melody told by her captors, I find myself wondering? And also...

Who Is Benjamin?

"Hello, Benjamin" seemed to be the trigger for River to launch into psychopath mode. Who's Benjamin? Is this a throwaway reference, or a clue of things yet to come?

What Happened With Kennedy?

Talking of throwaway references that could be clues about the future: "Time can be rewritten. Remember what happened with Kennedy"? Is that John F. that they're talking about, or someone else...?

What Does "Silence Will Fall?" Actually Mean?

A thought occurred during this episode. If the Silence are a religious order and not the name of the alien race from "The Impossible Astronaut" and "Day of The Moon," then... what if those aliens are actually working against the Silence? What if young Melody was in the astronaut suit because it was a way of keeping her away from the Doctor? What if "Silence will fall" is actually a reference about the failure of the attempt to kill the Doctor?

What Is The Question?

More importantly, the Silence is a religious order formed around one particular, unknown question... but is it really unknown? I can't help but wonder if the Doctor himself asked it this episode, as others have done more than once this season already: "Doctor who?" Would Steven Moffat really turn the title of the show - something that's never really made sense within the context of the show - into a plotpoint? And if so, what is the answer? That said, I'm fairly convinced that this will turn out to be what the question is, or something very close to it... We've seen more than enough suggestion about the importance of who the Doctor is - Ultimate weapon, ultimate hero, pacifist, curious old romantic who happens to be in the right place at the right time, or all of the above; think back to the discussion about what "Doctor" means in other cultures during "A Good Man Goes To War," for example - during Moffat's two seasons so far that I think we're closing in on the need for some kind of clarification of the Doctor's credentials as the best of all good guys.

(And here's an extra question: What's the significance of "fish fingers and custard"? Was it just a reminder of how much the Doctor loves Amy/Amelia, or something else entirely? I'm convinced something happened between that scene and his appearance in top hat and tails, and not just because he wasn't around for 31 minutes before he collapsed...)