Kristin Scott Thomas gets nasty at Cannes

• Kristin Scott Thomas stars alongside Ryan Gosling in the new film from Nicolas Winding Refn%2C %27Only God Forgives%27
• Thomas goes against type to play the foul-mouthed matriarch
• Actress was excited to break out of her customary %22upper-crust thing%22

CANNES, France — Kristin Scott Thomas is known for her cool, aristocratic demeanor in classic films such as 1994's Four Weddings and a Funeral and 1996's The English Patient.

But now it's time for her to get nasty. Real nasty.

The English-French actress, who turns 53 on Friday, takes on a very different role as the bloodthirsty head of a drug-running family hell-bent on revenge in Only God Forgives (out July 19). The film from writer-director Nicolas Winding Refn saw its world premiere at the Cannes Film Festival on Wednesday.

Thomas will shock — and delight — her fans as she chews her way through anyone in her path onscreen while inhaling long, thin cigarettes. The role has thrust her into the spotlight, a place usually reserved for her marquee co-star Ryan Gosling, who was pulled out of the festival because of last-minute film commitments.

"She had no problem turning on the bitch switch," said Refn as the film was introduced to the international press.

"It's quite frightening," Thomas added with a laugh.

The Hollywood Reporter was among the voices that instantly praised the "brilliant casting stroke."

The industry magazine summed up her character as "a platinum-haired, poison-tongued ice queen who conjures thoughts of Lady Macbeth, Medea and Tamora from Titus Andronicus, as styled by Donatella Versace."

You could throw in Salome as well, since Thomas' Crystal calls for the head of the people who killed her oldest son to be laid out on a platter. When told of the violent crimes that led to her son's death, she says with a shrug, "I'm sure he had his reasons."

Crystal dishes out the scorn in her first moments onscreen, when she takes down hotel employees who won't let her into her suite after a long flight. But she saves her most blistering venom for her younger son Julian (Gosling), who disappoints her by not exacting revenge.

During one lunch-from-hell scene, Crystal degrades him with discussions of his private parts and refers to his date by an entirely unprintable name. Refn says he incorporated the term into the script after asking Gosling for the most vile term that an American woman could be called. Thomas pulls it off coldly, but said she had trouble getting the word out when the cameras rolled.

"It took me eight takes to actually pronounce it," she said.

Thomas insists she was not trying to go up against her usual character type when she was offered the Only God Forgives role. "It kind of happened. When I first read the script I was so excited about playing someone far away from the upper-class thing that English people love to see me in. It wasn't like I needed to find a film that's going break this terrible shell I am trapped in. It was much more organic than that."

The role also got more "wild and savage" as the filming progressed and the script morphed. "I think if it had been set up weeks ahead I would have been terrified by it," said Thomas.

With Gosling on location in Detroit, it was left to the writer-director to defend the stylistic and brutal violence in Only God Forgives. It is even more extreme than in Refn and Gosling's first collaboration, Drive, which earned a director award at the 2011 Cannes festival. Refn referred to his approach to movie violence as "art" and said that he has a "fetish for violent emotions."

Thomas seemed to be a little surprised to find herself presenting her Crystal character to the world, saying the attraction for her was mostly the opportunity to work with Refn.

"This kind of film is really not my kind of thing," Thomas said. "This kind of violence... I don't enjoy watching at all."