Never seen it? Well, imagine a cross between Alien, Invasion of the Body Snatchers and Night of the Living Dead. Yet all of it is played straight down the line.

Peter Firth, in perhaps his most wooden performance since the halcyon days of Here Come the Double Deckers, plays the hero of the piece; an SAS operative who wastes little time in telling people that this is a 'D-notice situation' - whatever that means - and striding around looking like this is the most serious movie ever made.

The story opens with a space shuttle - piloted by Nicholas Ball - intercepting a spaceship buried in the tail of Halley's Comet.

A band of intrepid astronauts investigate the ship and find a collection of bat-like aliens and several glass coffins filled with gorgeous, naked young humanoids.

Three of the coffins are taken back aboard the shuttle and then all contact is lost.

A rescue mission is soon arranged and it turns out the shuttle has been gutted by fire.

I could tell you what happens next but all you need to know is that an alien plague befalls London, Mathilda May walks around in the buff a lot and wooden hero Steve Railsback and Firth try to get to the bottom of things.

An extremely tacky - and unintentionally hilarious - vampire saga from Tobe (Texas Chainsaw Massacre) Hooper.

A couple of years ago, I asked star Frank Finlay about the movie - a film which had intrigued him enormously.

For those who grew up in the Seventies, Finlay was the Des Lynam of his era. Smooth, charismatic and just about the suavest man on the box.

He was the actor most women wanted to sleep with, not surprising considering his turns in Dennis Potter's version of Casanova and Count Dracula.

For some, Finlay will forever be remembered as the Lothario in Seventies romantic drama Bouquet of Barbed Wire.

Of course, Frank never went away but for the millions of fans who can't get to the West End regularly, it seemed like his career has been on hold for 20 years.

Age may be catching up with the one-time sex symbol: The once jet-black hair is now a snowy white and the expressive, bushy eyebrows are going the same way. But he still carries himself with suave assurance and is immaculate in smart suit and pink tie.

His career has spanned nearly 50 years. Life in the business started in 1953. He won a scholarship for a two-year course at RADA and has been busy since his graduation in 1955. Over the years he has travelled from London's West End to Broadway and back again picking up a shelf-full of awards for his services to the stage and screen along the way.

He's made over 50 films including such classics as The Longest Day, The Loneliness of the Long Distance Runner and The Three Musketeers.

Frank received a CBE in recognition of his acting achievement in 1984 and a year later starred in one of the most ambitious and bizarre movies of his career.

In the multi-million dollar thriller Lifeforce, nude space vampires terrorised London and gave the likes of Peter Firth and Patrick Stewart a really bad day.

Finlay's VIP character became possessed by one of the aliens and ended up exploding into a mass of lifeless tissue.

It was hardly King Lear but he admits it was a lot of fun.

"It was good to do," recalls Finlay with a glint in his eye. "You see it was a very good script for that kind of story and I got on very well with the director, Tobe Hooper."

Making the movie reminded him of an earlier role he'd had which tapped into the same storyline and fed his fascination for such X-Files-type phenomena.

"There was a play I did at the National where the characters are talking about a room that has had a murder and they talk about the force of that body leaving the room. This is what Lifeforce was about. The force coming from dead bodies.

"Maybe sometime in the future they will be able to relate sound which doesn't disappear. If you could get high enough up in the atmosphere and tune in you would hear the sermon on the mount. They've got a science now where they can take sound out of wood. I don't understand it but it's fascinating.'

Er...yes Frank.

Finlay excels at playing serious parts. He has the sort of face that commands attention and whether he's up to his neck in turkeys for sitcom How Do You Want Me or tackling exploding aliens in mega-budget thrillers, he takes it all in his stride.

There were many roles which paid the rent but were far from memorable. Finlay admits he's made some bad career choices over the years by making some films he couldn't even spell the titles of.

"Aside from Lifeforce I did another space-type weirdy: Cthulu Mansions," he recalls. "This was made in Spain. I don't think it's been seen over here. It's a bit of a weirdo. My sons have seen it and it's not very well done. It was a funny old part but good to do."

No more 'space-type weirdys' for Frank this year. He's sticking with more down-to-earth roles. "I've just finished a tour of a Neil Simon play which we did just before Christmas and then immediately after that I started doing this and then I was also working on The Grand with Susan Hampshire. I've just been working in The Isle of Man."

He's also working on a film, Dreaming of Joseph Leas, with Rupert Graves and then has another project in the pipeline.

"I'm going to do a tour in the Autumn but I can't talk about it because it's not been finalised yet but I usually drift back to the theatre. I've been working solid for over six months so I could do with a holiday now."