PLEASE NOTE: THIS REVIEW CONTAINS SPOILERS. OUR SPOILER-FREE REVIEW IS HERE.

Considering the strong run that Doctor Who has been enjoying this year, it was somewhat inevitable that at some point, the brakes had to be slammed on.

So it proved with the generally underwhelming Amy’s Choice, for this writer’s money, the weakest instalment of the series to date. What’s particularly disappointing is that the ingredients were solidly in place here for something better. The problem was that the end result - if you'll forgive the cliche - was less than the sum of its collected parts.

In the first third, Amy’s Choice had the feel of being the low budget episode of the series (not necessarily a bad thing), given that it looked like it was going to be the Doctor versus a bunch of old people (who turned out to be a surprisingly good foe, before they got turned into yet another batch of aliens with a chip on their shoulder).

As the episode progressed, though, that feeling was dispelled, as gradually, more and more effects money made its way to the screen. Some of this work wasn’t too impressive – the creatures coming out of people’s mouths, for instance – but the sequences where the Tardis was gradually freezing were far more impressive. And by the end, it was clear that the low budget episode this was not.

What it turned out to be was an attempt to put together a mind-bending head scratcher, an episode where you’re unsure throughout what is reality and what isn’t. And the catalyst for that is the choice that Amy Pond ultimately has to make.

When we join Amy and Rory, they’re in Upper Ledworth, five years since they’ve last seen the Doctor, and with Amy heavily pregnant. Cue the materialisation of the Tardis, and the Doctor duly arrives to discover that Upper Ledworth is a very quiet place. Too quiet a place, as it turns out, save for the sound of birds that soon start following the Doctor around. It’s thus time to try and get to the bottom of the mystery, because quiet places generally equal deep trouble.

However, before they get a chance to consider this, the Doctor, Rory and Amy promptly fall asleep, and wake up in the Tardis. A bit of dialogue later and we work out that they’ve all had the same ‘dream’, and none of them have been on the pop either.

But is it a dream? Or is what’s going on in the Tardis the dream?

That’s the conundrum posed by Toby Jones as The Dream Lord, a potentially intriguing character who appears inside the Tardis, and knows the Doctor of old. He's full of mystery, is clearly in control, and for once, knows a lot more than the Doctor seems to.

And yet, sadly, in spite of the clear potential here, the character of the Dream Lord never particularly intrigues enough to have us requesting a return for him in the future. We’ve had the immense pleasure of seeing Toby Jones on stage, and he’s genuinely an outstanding actor. But here, he gets a role that never quite falls the right side of slightly annoying (not helped by the overuse of him cutting in and out of scenes in different places). Certainly the script does him few favours, and by second half of the episode, we felt that the Dream Lord seemed to have outlived his welcome, if not his purpose.

That said, he does seem to hold the key to what’s happening, and he basically explains the rules of the game. One world that we’re seeing is a dream, and if you die in it, then you’re still alive. One world, however, is reality, and if you buy it there, it’s game over. The job? To work out which is a dream, and which real.

The problem is that there’s never really any doubt that the village sequences aren't reality, and as the episode zips between the two, we have to spend more time in Upper Ledworth, when it’s the story of the Tardis crashing towards a cold star that feels slightly more interesting (albeit admittedly probably not enough to power an episode in its own right).

The core job of the episode ultimately feels like it’s there to bring Rory and Amy back together, which it does via a contrivance where Amy proves that she’ll die for Rory (thus making her choice, and presumably stopping her lurching at the Doctor in the future). Rory, bless him, is even willing to cut off his ponytail to get into the spirit of things.

But it can’t just have been us thinking it would have been far bolder to actually have the Upper Ledworth world be true? Appreciating that it’s an unlikely move for a show that goes out on a Saturday teatime, it would nonetheless have ensured that Amy’s Choice would be talked about and celebrated for some time, as opposed to its more likely life being buried at the back of a box set.

As it was, the episode felt like it cheated a bit, given that both worlds apparently happened to be dreams, caused by, er, psychic pollen that was lying in the Tardis’ time mechanics (sabotage, perhaps?). Thus, the Dream Lord, we’re told, is actually the Doctor. Which explains why the two characters knew each other so well.

Or is he? Is there more to him than that? We always think back to something like The Lazarus Experiment with something like this, where an episode that seemingly was unrelated to others suddenly had a big part to play in the narrative of the series. It'd be lovely if that could happen here.

Thus, was that an ongoing thread element when we got the reflection of the Dream Lord in the Tardis console at end of the episode? Possibly. For, that aside, we certainly didn't have any cracks or silences this time round, and aside from that reflection moment, this was every bit an unspectacular middle of the series instalment.

All considered, Amy’s Choice wasn’t a terrible piece of television, but it’s the first episode of this particular run that left us underwhelmed. And it doesn’t help, of course, that the standard had been so high to this point (yup, we still like Victory Of The Daleks).

The messing around with our heads didn’t really work for us, and Simon Nye’s script – surprising, given his pedigree – came across as really quite dry. It had its moments, such as the “what is the point of you” line, for instance. More moments like that would have helped. Amy's "can we not do the running thing" also felt like a bit of a nod to old Who again, although it's likely to be more with the fact that she was expecting at that point of the episode.

In short, though, this was script that really could have used a few more sparks (and a bit less Dream Lord).

Sadly, it didn’t really get them. So, while it brought Rory and Amy back together, and while it once again showed that Matt Smith is already utterly owning the title role, this isn’t an episode we can see ourselves returning to many times again in the future.

That said, we can see it being an especially divisive one, with many people far keener on it than us. Let the debate on that begin below in the comments...

Our review of last week's episode, Vampires Of Venice, is here...