As Professor Nick Cutter, Douglas Henshall is at the centre of events in Primeval in more ways than one – and he's enjoying every minute of it. Words: Paul Simpson

Were you itching to get back to filming Primeval?

Yes. Once you get the scripts, it starts to get a bit exciting, because you realise that the action sequences have all been upped. There's a new set of monsters. There's a new set of relationships and circumstances, so you get geared up for it. I was very much looking forward to it.

It's a job like no other at the moment. I don't think there's anything else on television that's near to what this is trying to do. There are seven episodes this series, and they're like seven little one-hour films. I think it's pretty ambitious stuff.

What do you think the appeal is? Have you been surprised by the success of the show?

No – I don't want to sound arrogant but I wasn't surprised that people liked it, because I thought it was good. You can never tell whether or not it's going to work out, but I was in no doubt that we had come up with something that was good, and that we'd done our job right. The fact that enough people watched it to commission a second series was great, and a nice affirmation for everyone, but I wasn't surprised.

You've said you liked dinosaurs when you were younger; does sci-fi attract you as a genre?

No, I've never been a fan of Star Trek, or anything like that. Star Wars I went for in a big way, but I was never a Star Trek fan.

Is it exhausting filming the action?

I'm always wary of saying "Yes, everyone's terribly exhausted," because in the grand scheme of things, it's great fun. Sometimes my legs aren't quite as young as they were, and Primeval is all about "Why walk when you can run – and why run when you can run fast?" Occasionally I'd think, "Do we really need to do this again?" Running on sand in the desert in 45 degree heat, with a 35lb pack on your back isn't the best way to spend the day, but I was so excited to be in the desert in 45 degree heat with a 35lb pack on my back that I didn't really mind.

Which desert were you filming in?

We were in Fuerteventura, which doesn't have a desert of its own, because it's volcanic, but it's only about 60km away from the Sahara. What looks like mist in the morning is sand coming over, and through time, there's wonderfully formed dunes that we could shoot on.

Did they let you ride the motorbikes in the first episode?

I rode a little bit. I was a bit annoyed that I didn't get to do more. Obviously I was quite happy to let the stuntmen do wheelies because I would probably have broken my neck, but I quite enjoyed doing a number of things on my own there. Half the fun of doing something like this is that you get to do stuff like that.

What was your most challenging stunt?

The only thing I did that I was a little unsure about was diving off a boat into the Thames over at Canary Wharf. I volunteered to do it, and in the sober light of day I thought, "The trouble is, you don't know how to dive and you don't swim that great... What are you going to do?" But I realised that I was wearing a wet suit that was pretty buoyant: it would have been pretty tough to drown myself. I was a little bit concerned about how well I was going to go into the water, but I was fine.

Did you get any injuries at all doing the stunts?

Yeah, I fell on my arse! We were filming in a forest for episode three, and they had dug this 10 foot hole. It had been pouring with rain, and it had all got filled up with mud and water. I've jumped in there to get away from a sabre-toothed tiger – it's jumping over the top and trying to get me. They put a wooden pallet in under the water to give me a little bit more stability. I jumped in and fell backwards, and my hand went down, right down on my thumb, on this wood. I thought I had broken it, but it's such a wussy thing to hurt. I couldn't really stop and say, "I hurt my thumb" having been insistent that I was fine to do the scene. I remember trying to finish and worrying that I was going to be sick – I thought I had dislocated it. But it was fine.

Was the shopping centre in episode one a bit like a big playground?

Yes, it was great, and it also has that feeling of [Terry Gilliam's] Brazil about it: all that gleaming white and metal, particularly the way it was shot and lit. I wish the shops had been open, because there's an awful lot of hanging around there while you're doing it. They're great shops and it's the only time you get to see them that quiet!

We started at sundown and finished at sunup. The first 10 days were night shoots, so it was a bit weird. Suddenly you're going from your bed to running around the Bentalls Centre in Kingston away from an imaginary velociraptor.

Was there a desire to make this series bigger than the last?

There's no point in doing another series unless you have the ambition to try and make it better. That was very apparent in the way Adrian and the guys wrote it. There's a lot more action sequences. In the first series we didn't have any dinosaurs because everything predated the Jurassic period – so to kick off with a Velociraptor was a good idea, and then we take a little bit of artistic licence with what the future might hold, which I think they've done very well.

I think the [new headquarters] ARC was a great idea. When I saw it, I thought, "Okay, so they're serious about this for a while." I don't think you'd build something that big otherwise. It was a little bit of a pat on the back for everybody.

When you get a script and see which monster you're facing, do you ever research the monster concerned?

Do you know, I probably should! I'd love to say "I do, I have a database at home," but I don't! The biggest thing is to make sure you try and pronounce things properly.

But your knowledge of dinosaurs must be pretty good now...

No. A woman came in from a TV station to do interviews with us on set, and brought a bag of plastic dinosaurs with her. She said, "You know your dinosaurs quite well then, do you?" I said I was alright. "OK, then what's that then?" There were four of them, but thankfully they were the four most obvious ones you can think of – I think I pulled off most of them.

Do you think the show has become more ambitious intellectually with the storyline about parallel time streams?

I'm of the opinion that kids of a certain age really like stuff like that to work out. Most of them are smarter than me, because they are prepared to go after something to work it out. The only people I think might find it confusing are adults, because they're either too lazy or don't care enough to go anything other than, "Och, that's a load of nonsense". Whereas the kids will go, "Hang on, I read something about that somewhere else..."

I think there's a constant fight: how much science goes in? I'm not entirely sure how many conversations go on before I get my script but I imagine there's a few where they go, "Science is boring, can't we put in more monsters?" I'd like to see a bit more science, because I think we can make it interesting.

Are we going to see a lot of differences in this new world Cutter has returned to?

That was maybe a trick we missed, insofar as there are little things that you could have done in order to make the world look like a different place but make it very subtle. I think if you make it subtle, it's more scary. I've often thought if you went back in time somewhere, what would freak you out the most? I think it would be the little changes, the little things that you'll never understand.

I don't think they had the time to do more, to be honest. That was the other problem: we didn't get recommissioned until March and then we were shooting in June. They had three months to get it together.

Are you looking forward to seeing the model of yourself?

I haven't seen it yet – God knows what it'll look like! It's a bit bizarre having a bit of plastic of yourself in the shop. It's a bit odd, but flattering.