Primeval has a problem. Okay, it has lots of problems. But its central problem is pacing.

Like a shark swimming along in the ocean, it needs pace. If it slows down, it collapses under the weight of two miles of silliness.

Now the first episode was just fine, nipping along fast enough that you could overlook the masses of plotholes. It was stupid but perfectly acceptable, particularly if you're a kid. The second episode slowed things down a bit, but filled in the gaps with great big giant spiders.

The third episode, though, committed the ultimate crime of being boring: a show about dinosaurs must not, should not be boring.

However, there are other problems. Hannah Spearitt may be 26 and there to appeal to kids, but having her dancing around in her undies is disturbingly close to a widescreen version of Minipops; having her flirt with a lump of man-granite (James Murray) and a student version of Norman Bates (Andrew Lee Potts) is probably illegal in most countries.

Then there's Dougie. Somewhere during the second episode - I probably blinked and missed it - Dougie Henshall must have been shot by a tranquilliser dart, because he's been wandering around with a dazed expression ever since.

This is probably because of the sub-plot with his wife. I'm sure it's supposed to appeal to the adults while the kids snort up the beasties like so much crack cocaine. But we're supposed to believe in a woman who's decided she'd quite like to spend time with dinosaurs back in the past, but doesn't trust her hubbie enough not to bring some of his mates, so fakes her own death instead? Then, after eight years, she gets a bit lonely and asks him if he'd like to come back with her, but instead of turning up at their house, she starts giving messages to his pals when they're close to death along the lines of “Why don't you come back and see me some time – about 80 million years should do it, love, and don't forget the weekly Sainsbury's shop, cos we're going to need plenty of loo rolls.”

All that time by herself and she has, to use one of my wife's expressions, gone doolally tap. No wonder Dougie looks dazed by it all. He's probably calculating precisely how much he's going to have to spend on psychiatric and hospital bills.

I'm not predicting this is going to get any better – in fact, it's probably going to get worse – so I'm probably being generous by declaring that Primeval has earned a three or “Minor Caruso” on The Carusometer quality scale. A three on The Carusometer corresponds to “a show in which David Caruso might guest star. If dinosaurs feature in it, it will be impossible to decide which is more convincing, him or the dinosaurs. Throughout the episode, he will insist on doing a 'cock-a-knee' accent that will make it impossible for any other actors to keep a straight face. He will then storm off set, shouting about how he can't work with amateurs.”