The fourth in Hammer's Dracula series, this film's most startling aspect is its subtext. I don't know if I'll ever see a clearer take on the theme of "vampires = sex", despite the lack of nudity. Flimsy nightdresses and plunging necklines, yes, but that's not what I'm talking about here.

It had previously been established in this series that Christopher Lee's Dracula was a sex god. Admittedly he didn't actually have sex with his victims, preferring the more traditional route of biting open their jugulars, but he was still a dangerous woman-chasing creature of the night who had them all panting for his tall, dark and handsome attentions. By this point it's blatant. It's impossible to believe this wasn't deliberate, especially when Lee pauses before moving neckwards to brush lips with Veronica Carlson while lying on top of her in bed. She likes it too.

However this time he has an opposite number. Just as Dracula is the dark seducer who steals our womenfolk and makes them bad like him, we also have a hero. He's called Paul and he's everything Dracula isn't. He's good-hearted, he's honest to a fault and I don't think he does anything with any woman despite the fact that one of them is his girlfriend and the other is a busty barmaid who's clearly up for it. You see, Paul's gay. That's only in the subtext, of course. He's going to marry Veronica Carlson and they'll be very happy together, but this is still a strapping young lad whose first scene involves taking off his shirt, talking about how he wants a different kind of life and kissing another man. That man later tells us why girls are useless. Paul's second scene begins with him bearing a bunch of (pink) flowers and getting greeted with "You're looking pretty."

Who will win: hetero or gay? Paul has a hidden weakness, though. He's an atheist. In a vampire movie, atheism stops being a lifestyle choice and becomes a major plot point. Together they fight over the women... and yes, as always it's only the women. Dracula would never attack a man. Young and buxom, that's how he likes them.

Eventually Paul sticks his mighty stake in Dracula, but that's not the climax! Could this get more blatant? Well, yes it could, but in 1968 homosexuality had only been decriminalised the year before. Incidentally I wasn't kidding about the stake's mightiness. It's bloody enormous.

As with Hammer's Frankenstein series, the fourth film was the one that really rang the changes. One senses a formula looming as early as Dracula: Prince of Darkness, but this is something else. The Count's growing some characterisation! For the first time since the start of the first film, he speaks! What's more, he has an objective. He's so pissed off that he's changed his modus operandi, going so far as to order his latest thrall to destroy one of his victims before she can rise again as a vampire like him. Public-spirited of him. He even has something of a relationship with those thralls, allowing them conversations instead of merely treating them as slaves. "You have failed me. You must be punished." For once there's some uncertainty about what Dracula's up to and what he might do next, which was just what the series needed to stay alive and move forward.

There's also some dark stuff going on at the village near Dracula's castle. The villagers are in denial about their plight, to the point of actively resisting people who want to fight Dracula. "If we leave him alone, maybe he'll leave us alone." That's bleak. Whoever thought up that insight into human nature wasn't in a happy place. There's also some surprisingly strong characterisation for Paul, who should have looked like an idiot for sticking to his atheist principles in a Dracula film but has instead been built up enough that you don't even question it. He's driven by the truth, studying in his free time to understand the truth and is always honest even if it's not what people want to hear.

So it's different. There's interesting stuff here... but it's still smothered under a blanket of Hammer formula. It's good. I like it. However if you haven't spotted the subtext, then this is probably going to look like just another Hammer film. You can tell that style a mile off, that slight staginess set against luscious but old-fashioned production values. It also has some extraordinary goofs.

1. The film begins with the discovery of a vampire's fresh kill in the church. Naturally she's dangling upside-down in a low-cut nightdress. Mmmmm. Sounds good, yes? Naturally you'd assume that Dracula has climbed out of that river in which we saw him drown and is back to his old tricks. However up at the castle our heroes find him still trapped under the ice, waiting as usual to be revived by blood. So who killed the girl? There's no mention of another vampire, or even acknowledgement by the other characters that such a thing is a possibility. On the contrary, Monsignor Mueller's logic to the villagers goes that since Dracula's dead, everything must be okay.

Admittedly that ice is laughably thin and it's possible that Dracula has been clambering out of the river, going off to feed and then returning to the freezing river to let the ice freeze back over him. Sounds unlikely to me. He likes coffins.

2. Dracula's final demise is hilariously contrived even by the standards of this series and "whoops, I just saw a windmill with cross-shaped vanes, aaaaargh". I kid you not, I laughed out loud. It has a strong punchline though, with a big decision for one of the characters.

3. Terrible day-for-night filming.

4. A dull performance from Ewan Hooper. They even dubbed over his lines with another actor. Admittedly he's useless in a better way than one might expect with Hammer, since he's completely convincing in his role and always sells the reality of his situation. The problem is that his only character point is "despair" and he plays that pretty much to the exclusion of all else. That's what he's like from beginning to end. The danger with such a role is that of becoming flat and one-note and that's the trap Hooper falls into.

5. A bizarre moment in which Hooper's character is supposedly translating a text on vampires. We're told that it's Latin. Furthermore if it hadn't been, then Paul wouldn't have needed to fetch a priest in the first place. However not only does Hooper play it as if he's reading verbatim, but the lines themselves include phrases like "lest the vampire try to gain ingress". Did everyone talk like that in his language classes?

6. Strange vampire lore, though that's admittedly a Hammer tradition. Would Dracula really be unkillable in a non-Christian country? That might explain why he goes for Chinese kung-fu in Legend of the Seven Golden Vampires. Although having said that, I think overall the script makes intelligent use of its vampires. All those silly weaknesses, for instance, are what makes the plot work. It's why Dracula needs his thralls and has to go to all these lengths instead of just walking up to his target and snapping his neck.

There's also some nice make-up for the vampire bites, while the fangs look good too. There are some silly-looking vampires in Hammer's early days, but these look fine.

In you can see beneath the Hammer house style, there's a lot to admire here. I've seen it called their most profitable film. Anthony Hinds's script is clever, down to little touches such as the villagers saying they don't go to church because it's touched every day by Dracula's castle's shadow. That's an eerie way of thinking. The script also finds good reasons for it never being daylight when a character finds Dracula's resting place. Then most importantly there's a deft touch with characterisation, for instance avoiding the obvious when Paul's girlfriend finds that buxom barmaid all over him in his bedroom. Well, it could have been worse. Given the role, I'm slightly surprised that they didn't get an actress with bigger breasts than Barbara Ewing.

It's a well made film, even though the director Freddy Francis was a last-minute replacement for Terence Fisher after a car accident. Freddy had been the cameraman, although in fairness at that point he'd also been a director for some years and already had one of the two Oscars he'd eventually win for cinematography. Sons and Lovers (1960). This film is perhaps a little less atmospheric than its predecessors, but that's partly due to the fact that the formula they're bucking was a good one. It's solid stuff even if you're not looking past the surface... but then there's that subtext.