This one is a true masterpiece.  I am of the belief that the Doctor Falls isn't quite as strong, but it is easy to look at World Enough and Time as its own thing, with its own focus, and its own ending.  Taken like that, this story is kind of perfect.  We start with something truly endearing and heartwarming.  After teasing Missy potentially wanting to redeem herself, we see her, I think, sincerely trying to be like the Doctor - going about the universe and inflicting a little good upon the worlds for once.  And then it all goes horribly wrong.

I love what they do with Bill this episode.  It's a true nightmare, it comes out of nowhere, and it is one of the most impactful companion deaths to date.  I truly despise how this moment is walked back later, but here, it is a stark reminder that there is risk to adventure.  And so this tragedy unfolds before our eyes in a way I found very creative and interesting.  The massive ship they were on with whole floors devoted to agriculture or industry and even artificial environments to reflect that is one of the coolest settings I've seen in any Doctor Who episode.  I also found the scene where the Master reveals himself and we see the fate of Bill to be really well done too.

This is one of those Doctor Who stories that really pays off the more familiar you are with the franchise. Lots of deep cuts and references to Cyberman history dot this story and it's second part, The Doctor Falls.

Focusing on just the first part though, World Enough in Time is so astoundingly good. Taking advantage of fun time dilation effects, while brilliantly showcasing the horror of the Cybermen in a clever and carefully built way, I have no notes for this episode. There's not a frame I think I would change, although the Black and White clip someone made of Bill's big scene, done in the style of Classic Who, really makes me wish there was a version of the episode edited that way, too. I still think it shows how well the source material lends itself to Classic Who and that particular brand of horror.

That's not even to mention all the great moments with Missy. Not only is there the big reveal with Simms, which was a lot of fun and I will fully admit I did not see coming on first viewing, but she just has these amazing moments right from the start. "Comic relief and Exposition" is just brilliant. World Enough in Time has a bit of cheeky fun like that here and there but at its core it is a gut-punch of a story. The Doctor is trying to do the right thing with Missy and instead gets his companion butchered, and the episode lives up to the breadth of such a thing rather well. This is a big deal and it is given that appropriate level of seriousness. Moffat very nicely strikes that balance.

Moffat also is really showing off his ability as a writer here. People will sometimes point out that every second the Doctor wastes explaining the situation regarding Bill is costing his companion large amounts of very valuable and precious time, but it is necessary for us as an audience and basically doesn't hold back the story one bit, because it is done with this sense of urgency and drives us forward into the heart of the story's conflict. It's all but perfect. Sure, some of the effects are more impressive than others, but it still looks great and is absolutely unforgettable as a piece of Doctor Who history. Currently rated as one of the best Doctor Who stories of all time, and deservedly so, I heartily recommend this entire Series, as the 10th season of the revived era is overall is one of my absolute favourites thanks to stories like this.