I have been remiss concerning reviewing this season of Doctor Who. Sometimes I get in the mode where I just want to enjoy something- a series, a book, a game- and not have to worry about analyzing it after the fact. But under the direction of head writer Steven Moffat, Doctor Who has become much more intriguing, a multi-level puzzle that rewards multiple viewings and which has shown how well the series can work with a darker, more sophisticated tone. After having spent several years watching Lost and enjoying the multitude of twists and red-herrings, I figured that I was done with a show like that for a long while. Doctor Who has sucked me right back in with the ongoing mysteries over the past two seasons: what is the truth behind the Doctor’s apparent death in the 6th season premiere, “The Impossible Astronaut”? How was the TARDIS destroyed late last season (only to get better)? What is the truth behind River Song?

It’s this level of commitment to the series that has me writing about it again.

After the bombshell dropped in the mid-season finale (in the previous episode, “A Good Man Goes to War”) regarding River’s true identity, we pick up with the Doctor, Amy, and Rory being forced to go back to Nazi Germany to- what else?- kill Hitler. This turns out to be a piece of misdirection as Hitler turns out to not be the true target, and along the way, miniature ray guns, robot ships, and several other surprises pop-up.

In some ways, “Let’s Kill Hitler” is more of a game changer than “A Good Man Goes to War”. Whereas in the previous episode, we discovered the truth about River’s identity, here we find out her true nature. Along with that, one of the lingering subplots for this season is wrapped up (just what was the deal with that girl regenerating at the end of “Day of the Moon”?), while some intriguing questions are tossed out (What is the question the Silence are awaiting the answer to?). Purely from an arc perspective, “Let’s Kill Hitler” moves things forward in a big way.

But the arc trappings take a back seat to the building blocks of the episode. Alex Kingston’s manic performance as River really steals the episode, providing her with some wonderful interplay with Matt Smith’s Doctor and some of the best lines of the episode (her comment to the Nazi soldiers is pure gold). The humor that underscores the episode is never forced, and Moffat plays the script a little fast and loose to good effect. Karen Gillan and Arthur Darvill have really settled into their roles as married companions, their chemistry being spot-on. When caught in an apparent death trap, their subtle profession of love to one another is wonderfully played.

The episode falters in a few areas. The robot ship and its crew are a bit silly for a few reasons. First, their lack of foresight in determining what year it is before enacting their plan to kill Hitler is a far-fetched. The fact that they would have killer robots on board that they would have no easy way to deactivate is another groan-inducing contrivance.  Not too mention, they seem to give up on killing Hitler a little too easily, as well as later flip-flopping their target from the Doctor to River.

I love that Doctor Who is back to complete the 6th season, and Moffat’s story doesn’t disappoint. With a number of twists and a generous sprinkling of humor, “Let’s Kill Hitler” is one of the best episodes of the season.

Rating (out of 10): 9