Cannes has been waiting for Lynne Ramsay

— “Maybe I should be a literary agent,” Scottish director Lynne Ramsay says puckishly. “I’m good at picking up on books that become successful before it happens. I could pick up a lot more money than making films.”

Ramsay is not just referring to Lionel Shriver’s novel “We Need to Talk About Kevin,” the source of her latest movie and a book she wanted to film well before it became an international success and won Britain’s Orange Prize for fiction. She is also talking about “The Lovely Bones,” a novel she caught on to early and spent five years writing a screenplay for, only to have Peter Jackson make a very different film. The situation, she says frankly, was “a debacle.”

A lively woman with a musical Glasgow accent, Ramsay laughs easily and has a sense of fun about her. With “Kevin” screening in competition at Cannes, she has made the kind of successful return to the film festival that everyone was hoping for. A tragedy in multiple keys, difficult to watch but impossible to turn away from, “Kevin” reinforces Ramsay’s reputation as a director in complete control of all aspects of the medium — a reputation she began building with award-winning shorts and her 1999 Cannes feature debut “Ratcatcher,” a film that won her the BAFTA prize for best newcomer in British film.

Co-written by Ramsay and her husband, Rory Stewart Kinnear, “Kevin” provides another showcase for the formidable acting skills of Tilda Swinton, who is on fire as a mother attempting to come to terms with her life after her son’s part in a high school massacre. With a raw yet controlled performance that covers a wide emotional spectrum, Swinton has to be an early favorite for the festival’s best actress award.

Ramsay was interested in adapting the novel because she saw it as a family story that had parallels to Greek tragedy. “Families are so complicated,” she says, drawing on a cigarette. “My brother and my mother had a really difficult relationship; he would exasperate her to death but she’d always be there for him, she always loved him even if she didn’t like him at the moment.”

Such is the case with Eva (Swinton), who has a starkly ambivalent relationship with son Kevin. “It’s one of the last taboo subjects: You’re meant to instantly love your baby from the moment he’s born, but what if you don’t?” Ramsay says. “I love genre, and I saw this as a chance to subvert the drama a bit, to make a psychological horror story.”

Swinton had long wanted to work with Ramsay. “She took me by the scruff of the neck,” Ramsay remembers with a laugh. “She took me to lunch, got me drunk and said, ‘You better cast me.’”

Ramsay did and never looked back. The actress “comes from Scottish aristocracy, her family is military, she’s an Amazon, bold and brave,” the director says, citing as an example Swinton’s willingness, for the movie’s opening scene, to be filmed “among 40,000 drunk people” in Spain’s famous food fight known as the “running of the tomatoes.” “It felt dangerous, really touch-and-go. The crowd was mental,” Ramsay says. “Tilda is not a diva.”

Though she works expertly with actors, Ramsay is an exceptional visual director. “Lynne is an instinctive filmmaker; she’ll make an image without being aware of what it means,” Swinton said at a news conference after “Kevin” screened. And Ramsay herself says, “I can see films in my head.”

This visual sense has been with Ramsay since childhood. “My mum says I was the best kid ever; you could put me in a corner with a box of paints and I’d be happy for hours,” Ramsay remembers. “They’d say, ‘Lynne, Lynne,’ and I wouldn’t hear them.”

Because of “Kevin’s” flashback structure and a 30-day shooting schedule that often required 25 setups a day, planning was “a huge logistical nightmare” that worked only because Ramsay and Kinnear moved in with cinematographer Seamus McGarvey and collaborated with him on pre-production for two months without anyone being paid.

Though directing again after nearly a decade off proved to be “like riding a bicycle,” Ramsay continues to be troubled by “The Lovely Bones.” “It killed me, it knocked me for six,” she says. “I thought I was writing something darn decent and I felt a bit betrayed at the end.”

Starting the project before the book became a phenomenon, Ramsay was “much more interested in the inner world of the father, whether he was going to see his daughter, like Hamlet and the ghost.” But after the novel took off, “they wanted a replica of the book. It was a horrible time, no one was telling me the truth, like ‘1984.’ They’d say, ‘Yeah, we like it, but can we make it a version of the Susie we know and love?’”

All this intensified, she said, “after Peter Jackson started sniffing around”; leaving the project “became a bit of a mutual thing. I was getting so frustrated, it would wake me up in the middle of the night. It was so hideous, it made me question whether I wanted to be a filmmaker or not.”

To experience “We Need to Talk About Kevin” is to be grateful that the answer was yes.

kenneth.turan@latimes.com