Who, as the tagline for one of the most popular movies ever made asks, you gonna call? Not Ernie Hudson, it turns out. At least not first.
He's giving a talk at the London MCM Expo, where he's come to promote the new Ghostbusters game. But by his own admission, Hudson was not top choice for the job. "In the scheme of people who they go to, I'm like, the last guy," he tells the audience. "They assume I need the money. Which is true."
In fact, as Hudson explains later, he's done rather well out of Ghostbusters. Winston Zeddemore didn't get nearly as much screen time as the other three leads, but 24 years on the actor who played him is still recognised the world over. He's still getting paid to promote Ghostbusters products and he's still making money at sci-fi conventions.
He's arguably the star attraction at this one. Sure, Edward James Olmos is signing autographs over there in the corner. But Hudson was famous long before Olmos started shouting made-up swearwords at pretty robots, and besides, he's charging GBP 20 a time.
In typical circumstances Hudson would be doing the same. "Usually I do these conventions, and I sit at a table and I sell autographs to you guys for 15 pounds or something. Which is really kind of cheesy," he says. "But I'm down here for the guys who made the Ghostbusters game, so I'm here to sign for free. You can come by without worrying I'm going to take your money. If you want to take photos, feel free. Come by and say hello."
He's just as friendly when we sit down for our interview, full of smiles and promising to answer all my questions even if he's heard them a hundred times before. He doesn't pretend to be a huge gamer. "But my sons, they're really into games," Hudson says. "So when they asked me to do the voiceover for the game, one of my boys came with me. He played it and he really liked it a lot. He was very impressed with it."
Certainly more impressed than he was with the Commodore 64 Ghostbusters game. "My kids really hated that. They thought it sucked. When it's your movie and your kids are saying, 'Dad, this game really sucks,' it's kind of... Hmm. So hopefully this game will be better than the first game. Hopefully they'll like it, and you guys will like it."
It's not that Hudson's never played videogames, he explains. "Years ago, I bought my son Tetris. He said, 'Wow, this is cool, Dad, but are you sure you don't want to play? Here, this is how you do it...' So I start playing Tetris. I have to be at work at six o'clock the next morning. Then it's 4.30am and I've been up all night, playing Tetris."
It is a tragic and all-too familiar story; Hudson soon found himself in the grip of an addiction that would go on to almost consume him. "For 15 years, I was hooked on Tetris. I played it every single day," he confesses. "I can still hear that stupid song in my head. I thought, if that one game did that to me... I just don't have time for that. So I'm not a gamer. But the kids, they spend more time than I'd like to see them spend playing games."
Well, everyone needs a hobby. And one that doesn't involve leaving the house is probably preferable if going out in public means you have to put up with people shouting, "Who you gonna call?" at your Dad every eight minutes.
"Yeah, there's always someone shouting that, like I've never heard it before," Hudson says. "I notice now the kids don't like going out. I'll say, 'Hey, let's go to the beach!', and they'll say, 'Nah, there's going to be a lot of people there.' Because when there's a lot of people, they tend to intrude."
Hudson has plenty of stories about being recognised, and they're all told with a sense of humour - despite the fact it doesn't sound like being a Ghostbuster is much fun sometimes. Take the time he tried to visit the Statue of Liberty with his kids. He was spotted on the Staten Island ferry by a man who then ran round the boat shouting, 'Hey! The guy from Ghostbusters is on there!'
"So I spent the whole time going to the island signing autographs and stuff," says Hudson. "Then when the boat docked the guy ran off the ship going, 'Hey! It's the guy from Ghostbusters!', and more people came over. So I never left the dock. The kids ended up going there without me."
Then there were all the times he had to answer his door to strangers, before he moved to a gated community in LA. "People [in the neighbourhood] would say to visitors, 'Hey, you seen that movie Ghostbusters? You know that black guy? He lives at number 1076. He's really nice, you should go by and say hello.'"
Because Hudson really is really nice, he'd open the door and say hello back - but it all got too much. "Sometimes people just want to talk about the marshmallow man, and that's cool. But it's not a conversation you want to have at your door, with people you don't know, at 11 o'clock at night."
Still, sounds like Hudson accepts intrusions as part of the price you pay for being in a hugely successful film. He also accepts the fact he'll always be remembered as the fourth Ghostbuster, although he had a much bigger part in the original script. "I was the guy who got slimed in the hotel, but I guess the studio felt they wanted more stuff for Bill Murray," Hudson reveals. "I was the guy who thought of the marshmallow man on the rooftop, but then it became Danny [Akroyd]'s character."
It was only after he won the part of Winston that the decision was made to reduce the character's role. "And they didn't do that till the day before we started shooting, so I didn't have time to adjust," Hudson says. "Yeah, when the part was cut there was some frustrating stuff associated with that. But it was what it was, and it is what it is. 24 years later, people still like the movie, and I'm glad."
Perhaps we'll see more of Winston in the Ghostbusters game, which is due out this autumn. It'll feature voiceovers by all four of the movie's stars, a script by Dan Akroyd and 75 minutes of music originally scored for the films but never used. Sierra is billing it as the sequel that was never made. Which makes you wonder why they never did make a third film...
"Danny [Akroyd] and Harold [Ramis] wrote an earlier script. They were trying to create a way where we could turn the franchise over to some younger guys, but they just couldn't get Bill to sign off on it," Hudson says.
"I know they've been wanting to make it happen, they've been trying. But I'm told Bill Murray has been the hold-out. I'm not quite sure why they have to have his approval. Something is going on there. But I know it wasn't from a lack of interest from the studio, or from a lack of interest from Harold and Danny."
So would Hudson sign up to appear in a new Ghostbusters sequel? "Me? Hah! Please," he jokes. "As long as they pay me well. My oldest son would tell me not to say that. But the truth of the matter is, I can be bought off." And then he adds, brilliantly, "For the right amount of money, I'll believe anything you say."
The rest of the interview passes in a bit of a blur, as I have fallen completely in love with Ernie Hudson. He may be the fourth person they call, but with his big smiles and funny jokes and charm and honesty, he could sell me anything. I am transfixed as he tells a story about a party at Ray Parker Jr.'s place ("His house is twice the size of mine. That song really paid well"). I am strangely fascinated to learn he missed breakfast with Edward James Olmos earlier. I could sit here all day.
But I can't, it turns out; the PR man is signalling I have one question left. Except I don't have any questions left, just a notepad full of scrawls about downloadable content and why movie tie-ins are rubbish and none of it seems relevant. So I scratch around in the depths of my brain, and somehow manage to come up with the worst interview question ever: "What's the best thing about being a Ghostbuster?"
"Hmm," says Hudson, while I attempt to pull my own head between my shoulderblades in shame. "I don't know if this is about being a Ghostbuster or an actor or whatever, but...
"Sometimes when I'm walking down the street, anywhere in the world, I see somebody on the other side of the street, and you can just tell his life sucks by the way he's walking. There's a cloud over his head. You see people who are homeless, who are having a hard time.
"They look up and see me, and they recognise me. And they go, 'Oh, sh**! Oh man! Oh wow!", and the cloud kind of disappears. They say, 'Wow, man, we're really happy to meet you.' Then they say - I get this all the time now - 'You're my mother's favourite actor. Can you sign this?'
"After that little exchange they walk away, but it's a different walk. That doesn't cost any money. And I think it's pretty cool."
Few people could tell a story about making homeless people happy without sounding arrogant, but Ernie Hudson can. Partly because he tells it with humour, and partly because you can tell meeting him makes people happy. I go to shake his hand and he gives me a bearhug instead, and I walk away thinking, 'I just hugged a Ghostbuster.' And it is a different walk.