Tilda Swinton plays the David Bowie-esque rock superstar Marianne Lane in director Luca Guadagnino's latest film A Bigger Splash -- and according to screenwriter David Kajganich, the character was in many ways the actress's own creation.

A loose remake of the little-known 1969 French film La Piscine, A Bigger Splash centers on the fraught character dynamics that emerge when Marianne and her boyfriend Paul (Matthias Schoenaerts) are paid a surprise visit by Marianne's overbearing record producer ex-lover Henry (Ralph Fiennes) and his coquettish daughter Penelope (Dakota Johnson) while vacationing on the Sicilian island known as Pantelleria. 

"Originally [Tilda's] character was an actress," Kajganich told me while promoting the film. "And what she was doing in Pantelleria in the film was basically learning an American accent for a part that she was about to play. And so there was always something built into even the first drafts of the screenplay that was about something conspicuous with her voice. But then when Tilda came on board, she said 'Look, I want to make a suggestion...about possibly moving Marianne from the world of acting into the world of music.'"

Swinton's pitch was, as Kajganich puts it, a "very wild idea," not only because it changed the character's profession but because it rendered Marianne -- who in Kajganich's original scripts had most of the dialogue -- near-speechless due to a recent throat surgery. 

"It took me a couple of days of thinking it through to realize -- not only was it doable, it actually was preferable," said Kajganich. "Then what we did was, Luca and Tilda and I got together for a week and kinda went through the script and the character and tried to figure out well, if we are only giving her a few lines, and she is this bold kind of performer, sort of this rock musician who has huge world celebrity, but who wants in our film to move towards a more grounded existence with Paul, how do we choose which things she's going to say and why? And of course obviously, we wanted her to say the things that were important for her to say as opposed to important for the audience to hear. 

"And so a lot of the lines that she does speak in the film seem at first maybe inconsequential, but part of what's so interesting about having a character who's actually hurting herself by speaking is that every time she does, you know it must be important to her."

At first watch, the things that Marianne chooses to say (or, more accurately, whisper) seem banal; in one early scene set at an outdoor restaurant, she informs the waiter that she's liked a daiquiri, and it's the first thing we ever hear her speak. But as Kajganich points out, it's no coincidence that Marianne says it not long after the arrival of Henry, who in flashbacks can be seen enabling Marianne's prior substance abuse.

"It communicates so much about how susceptible she is to being pulled into these past behaviors by Harry, and how alarming that is to Paul to hear her waste...a line of dialogue on a line that seems like it's just trivial, but actually it's not at all," he said. "Which is why the audience I think will lean into whatever Marianne says, because we know what it costs her to say it. It's just a really interesting dynamic to have between an audience and a character."

A character that -- all due respect to Kajgnich -- Swinton seems to have played a major role in creating.

A Bigger Splash is in select theaters now.

A former contributor to sites including MTV's The Backlot and Bloody-Disgusting, Chris Eggertsen worked in film development before indulging his love of pop culture writing full time. He specializes in horror, the intersection of social issues and entertainment and Howard Stern. He's on Twitter @HitFixChris.