Jon Pertwee’s fifth and final season as the Third Doctor is something that’s quite enjoyable to watch, if a bit melancholy. The tone of the season still has the same sense of swashbuckling, Steed-and-Peel Avengers-influenced derring-do of the rest of Pertwee’s time as the Doctor, but there’s also a sense of somberness to it. In many ways, it feels similar to David Tennant’s final run of specials and the four knocks – the blue crystal of Metebelis Three seems to be beckoning to the Third Doctor throughout his last season, letting him know that his time is indeed running out. And while it’s not the best of his seasons – the three middle seasons with Jo Grant were certainly his heyday of classics – with the introduction of Sarah Jane Smith to the TARDIS, it’s still an exceptionally good one.

Perhaps the best story of this season is “Invasion of the Dinosaurs,” a story than many classic Doctor Who fans have derided as a low point in the show’s long history … but that criticism is, in hindsight, unfair. Yes, if you ever wanted a poster child for why the special effects of the classic series were utterly atrocious, “Invasion” is the most obvious and easy story to point to. But if, as a viewer, you can get past that – and, admittedly, that’s a Very Big If for some – it’s one of the most surprisingly good stories broadcast during Pertwee’s time as the Third Doctor.

Why? Glad you asked. Let’s take a look, shall we?

Also, spoilers ahead – as much as a 43-year-old story can have spoilers, anyway!

“Invasion” opens with the Doctor and Sarah Jane Smith returning to modern-day Earth, where they find London virtually abandoned and under martial law. Mistaken by military patrols as looters (because OF COURSE THEY ARE), they learn that the city’s been cleared out because dinosaurs keep randomly appearing and disappearing on the streets. Why? And who’s responsible? That’s the mystery that the Doctor and Sarah Jane need to figure out, and it’s a mystery that eventually requires the full assistance of U.N.I.T. to solve.

It’s a story that’s kind of hard to neatly classify, despite the bonkers premise of time-traveling dinosaur invaders attacking London. In reality, “Invasion” is much more of a sci-fi espionage thriller/mystery – yes, really! – and it’s a surprisingly good one. “Invasion” is  a  complex, well-thought-out story, and unlike many of the typical six-parters of Jon Pertwee’s era, it doesn’t feel like it’s being stretched too thin. Much of the story involves the investigation into the cause of the dinosaur appearances, as well as the reason – and not everybody agrees on what’s most important to figure out first. Not even the Doctor and Sarah Jane are always on the same page, and while things invariably go the way the Doctor expects they will, it’s interesting to see the characters try to puzzle everything out.

Even once the basic mystery’s solved, it leads to further questions, and further problems, all of which are logical and fit the story . In this way, it stands out from many of the other six-part stories of this time frame, which typically resemble two separate stories stitched together with some plothole-ridden excuses of ideas. “Invasion” is  cohesive from beginning to end, and always manages to stay engaging and interesting throughout each of its episodes.

One of the big surprises in “Invasion” is how well-nuanced the so-called “bad guys” are in this story. Most Who villains of the Pertwee stories – and, for that matter, in “classic” Who, period – are pure evil, out to take over the world or destroy the universe, and the stakes of these stories are very clearly delineated into good/evil consequences. Here? Well, the main antagonists come in the form of Project Golden Age, a scientific group that has an agenda that seems oddly prescient: Humanity’s busy screwing up the world, possibly dooming it to extinction, and they want to set things right. That, all told, isn’t such a horrible mission. How they plan on accomplishing their goals isn’t exactly great – they want to send an elite group back in time and basically start humanity over, which would wipe out just about everyone in the modern world as we know it – but their basic premise of “making things right” is at least well-intentioned.

Also, most people in Project Golden Age aren’t even aware of the “wipe out humanity” aspect of the plan. So instead of a simple good/evil conflict, you have the Doctor and Sarah Jane finding themselves at odds with plenty of characters who are basically good people with inadvertently bad intentions. And it takes a bit more than a bit of Venusian Aikido to stop those good people.

It’s an interesting – and modern – twist. Fast forward the story thirty-some-odd years to another show in another country, and you could see pretty easily how “Invasion of the Dinosaurs” might be an episode of Fringe or the X-Files, without needing to edit much at all. Having Walter Bishop spout lines like “I posit that these dinosaurs are not being bred in modern times, but instead being brought here through a time corridor” … yeah. It’d work just as well now (and better with modern CGI effects, obviously!).

Most surprising in “Invasion,” though, is the twist of Mike Yates’ betrayal of U.N.I.T. – and of the Doctor! While Seventies Doctor Who really didn’t have much going on in terms of overreaching, season-long story arcs – at least not like it does in the modern era of the show – the recurring appearances of the U.N.I.T. regulars gave at least some backstory to the characters, and made them feel to regular viewers more friendly and familiar. You’d occasionally have the Brigadier grumbling about his wife, Doris, for example, or have a casual mention of Jo Grant and Captain Yates going out on a date, even though said date would never be shown on-screen. In the “classic” Who era, it’s probably as close as you get to character development like the Ponds, or Rose Tyler’s family. And U.N.I.T. certainly was a family.

So to see Mike Yates take sides with Operation Golden Age, and essentially sell out the Doctor, Sarah Jane, and the rest of U.N.I.T. – it’s both shocking and sad. Especially since Mike is like many of the other “villains” of “Invasion” – he thinks he’s doing the right thing, just for the wrong reasons. And when he finally realizes that he’s not only wrong and will have to resign from U.N.I.T., but that he’s also deeply disappointed his friends, and especially the Brigadier … man, it’s heartbreaking. This is watching it with modern television sensibilities, too – one can only imagine how shocking this must’ve been for first-time viewers in 1973!

On a more positive note, though, watching Sarah Jane in this story is awesome. I think most Who viewers associate the character primarily with Tom Baker’s Fourth Doctor, but it’s easy to forget how well Elisabeth Sladen worked with Jon Pertwee’s Third Doctor as well. “Invasion of the Dinosaurs” is a solid reminder of the terrific chemistry that they had together – it’s only their second story, but they work with each other with a great, natural ease. The Doctor’s still more than a bit patronizing to Sarah Jane, but that comes with affection, and you can see her understanding that he’s mostly trying to be protective of her (not that she always wants his protection!). It’s also great to see Sarah Jane still in full-on journalist mode – hey, dinosaurs overrunning London just might be a front-page story! So seeing her trying to help the Doctor out while still getting the scoop, and while trying to navigate security clearances, both from bad guy General Finch and from good guy Brigadier Lethbridge-Stewart … she’s got a lot to do in these six episodes besides say, “What is it, Doctor?”!

Everyone else in the story is pretty good as well. Pertwee’s in fine form here – even though it’s his last season (and he knew it at this point), on-screen, he’s still radiating the same flamboyant confidence as always. (Particularly when he finally gets to unveil the Whomobile in episode four!) And Mike Yates’ betrayal gives the U.N.I.T. regulars meatier dialogue than “five rounds rapid,” which is great to see. In particular, the Brigadier’s staunch but sad disappointment in finding out Yates is a traitor is terrific. Meanwhile, the guest cast reads like an all-star cast of other great classic Who episodes – hey, the evil scientist is Nyder from Genesis of the Daleks! And General Finch is Li H’sen Chang from Talons of Weng-Chiang! They give the excellent performances that you’d expect, so between the script and the actors, everything’s firing on all cylinders …

… except the dinosaurs.

The goddamn puppet dinosaurs.

Yes, the proverbial elephant in the room with “Invasion of the Dinosaurs,” unfortunately, are the dinosaurs … and yes, they’re every bit as bad as their reputation. Not only are they obviously puppets, they’re bad puppets, with primitive CSO overlay trying – and failing – to integrate them into the story. Every scene they appear in is utterly cringeworthy and laughably awful. There’s no way to take this seriously. Usually this era of Doctor Who was pretty good about knowing the limits of its next-to-nothing budget, but the dinosaurs show that the production team was clearly overreaching themselves this time – which is a shame, because if the story had been done with any sort of more conventional Who monster, I think it would’ve been a home run. I give them top marks for ambition, but in terms of execution, it’s one of the biggest failures in the show’s history. (I would love it if this could somehow get the “Day of the Daleks” modernized CGI effects options, which would probably allow viewers to see this story in a different light!)

Sigh.

Finally, “Invasion” represents a swan song of sorts for the classic U.N.I.T. era, which is both wonderful and bittersweet to watch. Already missing Katy Manning and the late Roger Delgado, U.N.I.T. was on the wane in its place in the Doctor Who universe, and “Invasion” is probably the last time we get to see the rest of its regulars – and the Third Doctor – operating at their finest. Yes, there would be more stories featuring U.N.I.T. over the next few years, but their impact in those stories isn’t nearly as strong. They’re basically off to the side of the main action in Pertwee’s final tale (“Planet of the Spiders”), and during their first few appearances in Tom Baker’s early season, it’s obvious that U.N.I.T.’s been relegated to an afterthought. “Invasion” is the story where you can see the curtain really begin to close, and it’s a good one to say a fond farewell to Brigadier Alastair Gordon Lethbridge-Stewart and his team, who meant so much to the stories of the Third Doctor’s era.

So, despite the dubious reputation of “Invasion of the Dinosaurs,” I highly recommend it as one of the best stories of the Third Doctor. And if you’re watching it on DVD, some of the extras are great – the Doctor Who Stories: Elisabeth Sladen Part One feature has the late Lis Sladen talking about her auditions for Sarah Jane, and working with Jon Pertwee. Some of the stories she tells are familiar ones, but it’s still nice to have them all in one place, being told by Lis herself. Also, People, Power, and Puppetry is a great “making of” featurette where both Terrance Dicks and Barry Letts talk at length about the behind-the-scenes work that went into making “Invasion” … and that, yes, even during the making of this story, they were acutely aware of how bad the dinosaurs were going to be.

At any rate, if you’ve never seen a Third Doctor/Sarah Jane story … I’d seriously recommend “Invasion of the Dinosaurs” as the one to watch, even with the terrible puppets. Even despite them, it’s outstanding.

Rating: 4/5 Braaaaaaaaaains.

–Mike