Killer Fashion: Anna Kendrick and Blake Lively on their new movie A Simple Favour

Blake Lively and Anna Kendrick star in A Simple Favour. For TimeOut.

Somewhat refreshingly for a mainstream release anchored by two movie stars, it's difficult to pin down exactly what kind of film A Simple Favour is. At times, the new Anna Kendrick/Blake Lively vehicle feels like a dark thriller in the mould of Gone Girl, at others it bears the unmistakable comedic touch for which its director, Bridesmaids helmer Paul Feig, is best known.

Sitting down with Kendrick and Lively in New York to discuss the film, both actors admit to initially struggling to identify Feig's tonal intentions while shooting the film.

"In a traditional comedy, you're on a slider from how subtle you can be to how broad you can be," Kendrick explains. "In the context of this film, you could kind of go in all dimensions. There's a lot of really naturalistic human drama in it and then there's a mystery, and there's kind of a Hitchcock vibe. Sometimes it's really grounded and sometimes it's really arch. So there were days when it was challenging."

"We were always checking in with each other because we were never exactly sure what the tone was," adds Lively. "So we would say 'Do you think I'm being too much? How far are you planning on going in this scene?' Because there were some very emotional scenes."

Indeed there are.

Kendrick plays Stephanie, a single parent with an online mummy vlog whose son goes to the same elementary school as the child of Emily (Lively), a glamorous and enigmatic fashion industry exec who takes something of a shine to Stephanie.

The pair tentatively ventures into a friendship and then one day Emily casually asks Stephanie to pick her son up from school...

Kendrick and Lively make for an instantly recognisable pairing as two women navigating the perils of trying to make friends when you're a grown-up. I ask if they can relate to the awkwardness such interactions generally entail.

"I don't have friends," responds a po-faced Lively.

"I have a self-fulfilling prophecy trying to make friends with other women as an adult where I'm like, 'They're not gonna like me', so then I act like a f**king weirdo," offers Kendrick. "It's easier for me to make friends with straight men and gay men and lesbians actually. I think I go into a self-defeating spiral sometimes when I try to make friends with a female as an adult."

Kendrick turns to her co-star expectantly.

"I wasn't joking," says Lively. "I really don't have many friends. I think I'm really awkward. Which is strange because in our profession we're supposed to be gregarious and charming and everybody gets along and I am so painfully shy. I think that's my thing that I struggle with: being shy."

In person, Kendrick and Lively reflect their on-screen dynamic to a certain degree: the former is chatty and warm, the latter laid-back and sardonic.

In keeping with her profession, Emily is an absolute fashion beast in the film, sporting several superlative looks that stick out in the film's predominantly suburban setting. Lively says she based the character's sartorial aesthetic on that of director Feig, who is famous for wearing exquisitely-tailored suits while on set.

"I saw a lot of Paul in the movie in general," says Lively. "There's actually a real power in having a costume and being a caricature of yourself. I thought, 'I need something as iconic and distinct as Paul', then I thought 'Why don't I just dress like Paul? That makes things easy.' I was nervous to pitch it to him, because [I thought] maybe he doesn't realise that he's almost like a caricature of himself."

After some convincing, Feig took to the suggestion and, consequently, more of the director's personality shows up on screen via Lively's character, who even rocks a skull-headed walking stick she took directly from Feig's collection.

"He has 450 walking sticks,"says Lively. "Gloria, his wife, is like, 'It's a problem'".

On the other hand, when we first meet Kendrick's character Stephanie, she's a somewhat severe people-pleaser who wears the daggiest outfits imaginable.

"Would I ever wear pom-poms with a denim skirt and a yellow and pink sweater and a floral kitty cat thing?" asks Kendrick, strongly implying an answer in the negative.

Although Stephanie goes through a transformation throughout the twisty film, Kendrick says she had issues with her character at first.

"I remember liking her immediately but there were definitely days when I was like 'Why won't she stand up for herself in this scene?' and Paul was just like 'Because she doesn't think she deserves to stand up for herself'. I felt like I, as Anna, wanted to stand up for her. And there were times when I was like 'This bitch needs to grow a pair'."

LOWDOWN
Who: Anna Kendrick and Blake Lively
What: A Simple Favour
When: In cinemas next Thursday