Right now, I'm currently in the middle of Season 17 of Classic Who. On the one hand, it's not one of my favorite seasons. Quite a few stories have good ideas but lack something in the execution. On the other hand, it has the brilliant serial "City of Death", which is always a joy to watch.
This is one of those stories that's so easy to stick on and watch when you've been having a bad day, or even if you just want to watch a great Doctor Who story. It's terribly clever, both with its ideas and its humor. It has some of the best quotable lines in Doctor Who history. And Julian Glover is brilliant to watch as the villainous Count Scarlioni.
There are few stories quite like "City of Death" in the Classic Series. Certainly, there are few stories that are as quotable or funny as this serial. Season 17 overall did include more humor compared to previous seasons, but none of the transmitted stories quite matched it in terms of quality.
When Season 18 came along, the show's style had changed significantly, with humor exchanged for a greater emphasis on harder science-fiction and arc storytelling. We never really had any stories quite in the same style as "City of Death" again. Not until the 21st century, at least.
The New Series
When Doctor Who came back in 2005, it brought with it a strong sense of humor. A sense of humor that was clearly influenced by "City of Death", if not by Douglas Adams's style in general. While plenty of Classic Who had its funny moments - Trougton's era is certainly a good example - the quirkiness and even silliness featured in "City of Death" feels the closest to the New Series's style.
For example, it's easy to imagine almost any of the 21st-century Doctors delivering iconic lines like, "What a wonderful butler! He's so violent!" But it's harder to imagine many Doctors from the Classic Series delivering the same line.
There are also the often quirky conversations shared between the Doctor and Romana. The constant back-and-forth between these two feels like an influence on Steven Moffat's writing. Particularly in the conversations shared between the Doctor and River. While those conversations tended to be much more flirtatious, there's still the sense of two incredibly intelligent equals who enjoy discussing complete nonsense. And that kind of banter between the Doctor and Romana is at its best in "City of Death".
Strong threat
However, what makes "City of Death" such a strong story isn't just its use of humor. It's also how much it balances that humor against an equally strong threat. Particularly when the funny lines are delivered by Count Scarlioni.
While Scarlioni delivers several hilarious quotes, none of them take away from the threat of his character. If anything, they only help to highlight how dangerously clever he is, making him an excellent opponent for the Doctor to face.
While not massively common, we do see this style of villain in the New Series. In fact, we often see it with some of the show's biggest villains. For example, newer incarnations of the Master and the Toymaker have used humor as a big part of their character. Again, that humor is often used to add to their sense of threat rather than detract from it. The fact that it's saved for some of the most popular villains highlights how strong Count Scarlioni is as a character.
Clever ideas
Lastly, there's also how clever the story is. "City of Death" takes place over millions of years, and features some of the smartest use of time travel - or at least time - that we've seen in Classic Who. For example, Scarlioni ensuring that seven Mona Lisas are painted by Leonardo da Vinci in the 16th century so that they can be sold to multiple buyers in the 20th is such a simple but brilliant idea.
That kind of cleverness with time travel is best seen in Moffat's stories, both as a writer and as a showrunner. You can tell with most, if not all of Moffat's stories how influential Douglas Adams's style of writing is. Every one of them has a strong element of humor to them.
But many of Moffat's stories also have something clever about them, too. It could be a neat use of time travel, such as the Doctor meeting his wife in the wrong order. It could be playing with a story's structure, such as Donna living a computer-simulated life - a life that's been heavily edited.
Perhaps one of the best examples of Moffat being influenced by "City of Death" is the 50th-anniversary special "The Day of the Doctor". Smart, witty conversations, clever use of time travel - even an enemy waiting centuries to get what they want - all of it feels like a great nod to "City", while still being a great story in its own right.
Regardless, there's no denying that this sense of storytelling - of clever ideas mixing with a strong sense of humor - owes a great debt to Douglas Adams, and to "City of Death" in particular. It's a story that has long been a fan-favorite and will continue to be for many years to come.