Sci-fi chiller Little Joe centres on a sinister plant that makes people who sniff it alarmingly happy. Laura Harding sits down with star Emily Beecham to learn more.

You do not have to get too far into the chilling sci-fi film Little Joe to sense that something is not quite right.

Actually, maybe you realise it straight away, that feeling of hypnotic unease lurking somewhere in the back of brain as it creeps further and further forward in your consciousness.

"It is really psychological and scientific and paranoid and mysterious and dark and awkward and loads of great things," enthuses its star, Emily Beecham.

"And it has Ben Whishaw in it," she adds. "And I've been a huge fan of his since I started acting."

Beecham is remarkably chipper for someone sitting next to one of the more sinister plants to ever appear on film.

The red spiky creation is the Little Joe of the title, not dissimilar to a Venus flytrap, and is perched on a small coffee table to her right.

"I'm not going to say what they are made of, because apparently, it takes away the mystery," she jokes.

"But it is so pretty, it's a bit like a fraggle."

In the film, Little Joe is a top-secret strain of genetically engineered plant, whose microbial scent will make people happy, created by Beecham's workaholic scientist Alice.

Take one sniff and it transforms your mood. You feel happy but also changed, not quite yourself.

Written and directed by the Austrian film-maker Jessica Hausner, making her first project in English, the movie is almost chilling in its cold and clinical crispness.

Most distinctive are the shots when the camera hovers near the ceiling of a huge greenhouse, containing rows and rows of precisely arranged plants.

"Jessica has this artist brain, she sees everything so visually," Beecham says.

"And when I met her, she showed me the picture of the plant and a lot of the aesthetic and the colours - it was so vivid.

"We called the greenhouse the plant house, and it was massive, it was amazing.

"It was actually the nicest set to go to, because when you wake up at 5am, lots of sunlight is really great and it wakes you up."

She adds: "There was so much sunlight beaming through every day and the plants were so stunning and in the next rooms there were actual plants - because it's an actual plant house - and there were all sorts of unusual things in there. We would go and have a little look, it was quite therapeutic."

The same cannot be said for the film itself, which sustains its mood of premonitory dread over the entire running time, as people who come into contact with the plant turn into sinister, conformist versions of themselves.

They become placid and not quite engaged with the outside world.

Alice's son Joe, who cares for the plant she has taken home, turns quietly indifferent, Whishaw's character Chris, Alice's colleague, goes from attentive romantic to worker drone.

"Jessica was inspired by Stepford Wives, Frankenstein and Invasion Of The Body Snatchers," Beecham says.

"But the difference is the acting in her films is very natural - it's all about what's going on in the character's head all the time.

"My character especially is very cerebral, in her head and a bit repressed. So she is always thinking and is constantly on this journey, trying to figure out what's happening.

"So, I had to pretty much ignore the genre and ignore the set, because my job was to be as natural as possible and ignore all this other stuff - that's the tone of her films."

She adds: "Ben and I would have a joke together that you couldn't completely plan what you were going to do on that day, because you never knew what idea Jessica was gong to come up with.

"She always comes up with such an unusual and original, totally surprising and really funny idea, and the character is always having this awkward dynamic. There is always this subtext between all the characters, especially between Alice and Chris.

"They have got this romantic, or not romantic, competitive relationship, but also humiliating and an awkward attempt at romance between them, so we were always discussing what was happening because it's all shifting."

Hausner may have been inspired by Invasion Of The Body Snatchers, but this time, the story is told in the age of psychopharmacological drugs, with Little Joe perhaps seen as a different kind of anti-depressant.

It is telling that those who are affected by the plants become slavishly devoted to protecting it.

As they settle into their new state, in a cult of their own well-being, no-one is allowed to question it.

But any comparisons with anti-depressants are apparently merely in the eye of the beholder.

"We never discussed that, but Jessica was always keen to say that that wasn't her intention," Beecham says.

"But also, we did talk a bit about what your perception of happiness is and how that is different for everybody, and what somebody considers materialism or love or career satisfaction or the Buddhist idea of contentment, just being.

"Happiness is subjective and it is different for everybody. What is happiness? That is really the question."

Little Joe is released in UK cinemas now.