Well that was quite an emotional ride, wasn't it? But then again, perhaps that was to be expected. After all, "Joy to the World" might very well be the final Doctor Who story written by Steven Moffat. If so, is it a good final story for the former showrunner? Let's take a look.
When the episode begins with so many different time zones, we're almost led to believe that it's going to be a complex story filled with timey-wimey shenanigans. The timey-wimey part is true, at least. The best example of this is when the current Doctor is aided by their future self, complete with bootstrap paradox.
But if we look at the episode as a whole, the plot is surprisingly straightforward: a weapons manufacturer has created a "star seed", which is exactly what it sounds like. When activated, it will wipe out life on planet Earth. The Doctor aims to stop it with his new friend Joy, but at the end of the story, Joy takes the seed into herself and lets it detonate far away from Earth.
That's a really light plot for a Doctor Who story. And that's OK. Because that lightness allows Moffat to focus on other elements.
The Doctor's loneliness
From the beginning, a major aspect of this episode is the Doctor's loneliness. He's still missing Ruby after saying goodbye to her in "Empire of Death", and you get the sense that he's looking for a new companion, even if he's not consciously aware that's what he's doing. Oddly enough, while Nicola Coughlan's character Joy is a key part of this episode, she feels like just one of three "new companion" options.
The first the Doctor meets is the lovably dim Trev, who works at the Time Hotel. While he's rapidly confused within seconds of meeting the Doctor, his eagerness makes him a likable character, which is only helped by Joel Fry's performance.
So when he's killed off mere minutes after promising not to let the Doctor down, it comes as quite the emotional blow. Steven Moffat was always good at comedy, but he doesn't let us forget that he's also good at gut-punching emotional moments.
An unexpected friendship
Technically, the second companion option that the Doctor meets is Joy, but he knows her for only seconds before he finds himself stuck on Earth for a year. This leads to the Doctor working at the hotel that Joy was staying in. More importantly, it leads to an entirely unexpected friendship with Anita, the hotel manager.
This is my favorite part of the episode. Plotwise, the Doctor staying on Earth for a year doesn't contribute anything at all. But the friendship he makes with Anita - a character you'd expect to only appear in the opening scene - is beautiful to watch.
As soon as we see the two characters start to like each other and play board games once a week, we feel a deep mix of emotions. Because while it's great that the Doctor is making a new friend, we also know that it's not going to last. So it's a genuinely moving moment when the Doctor has to say goodbye to Anita after a year.
Joy
It's funny that by the time the Doctor is reunited with Joy and focuses on trying to save her life, she's already been overshadowed by two other characters. Moffat still gives Joy some emotional weight with her grief for her mother on Christmas, but overall, it feels like the Doctor and Joy barely have any time together.
It's a bit of a shame, especially as Nicola Coughlan is a great actress. (While I've admittedly never watched Bridgerton, Derry Girls is one of the best comedies of the 21st century.) As brilliant as the Doctor's friendship with Anita was, it does take away a lot of focus from Joy.
The story at least is straightforward enough to include a few more emotional moments before the end - and some even afterwards. Getting to see Trev survive in some form, even digitally, brought a smile to my face, and we had a brief moment when we saw Ruby again. Again, these moments feel like they could overshadow Joy's story, but getting to see her final conversation with her mother partly makes up for it. Partly.
Overall, "Joy to the World" is a light but emotional Christmas special for Ncuti Gatwa's Doctor. If it is the final episode written by Steven Moffat (and that of course is a very big "if"), it's not a bad episode to bow out on.