Kristen Stewart and Laura Dern play the two woman who successfully pulled off a major literary hoax in the early 2000s by posing as JT LeRoy, the fictional wunderkind author with a tawdry childhood.

The deservedly forgotten 2004 feature The Heart Is Deceitful Above All Things has been in the news lately as a result of allegations of sexual misconduct against director and star Asia Argento, years after shooting wrapped, with her still-underage co-star Jimmy Bennett. The development and production of that project, along with an inflated depiction of its Cannes premiere, are central to Jeremiah Terminator LeRoy, with Diane Kruger stepping in as a deliciously opportunistic actress-filmmaker, here named Eva. That salacious connection to recent headlines should give Justin Kelly’s pedestrian account of the literary hoax behind it an extra frisson. But deceit is heartless, above all things.

Actually, a lot more than heart is lacking in the plodding, psychologically anemic script Kelly co-wrote with Savannah Knoop, based on her memoir about being drawn into the scandal that fooled book critics and readers alike in the early 2000s. For a movie about what’s going on under the elaborately staged surface, it’s pretty much all surface, right down to its shallow observations about gender fluidity, queer identity and the creative freedom of the alternate persona. After its premiere as Toronto’s closing-night gala, this looks to be headed fairly swiftly into streaming exile.

The movie’s feebleness is no fault of the always watchable Kristen Stewart, who turns on her androgynous mystique as Savannah, even before she starts donning the platinum bedhead wig, the dark shades and the raccoon penis bone strung on a lanyard around the neck of fictitious author JT Leroy. The movie makes a mildly compelling case that Knoop was dragged along for the ride at a vulnerable time while she was still figuring out who she wanted to be, pulled in too deep before she had time to contemplate the fallout. But that doesn’t make Savannah the rightful protagonist of this story.

That would be Laura Albert (Laura Dern), the partner of Savannah’s musician brother Geoff (Jim Sturgess). She created the pseudonym of JT, the son of a West Virginia truck stop hooker, frequently disguised and passed off as his mother’s little sister because it made her customers less uncomfortable. JT became a publishing sensation with gritty “autobiographical” writings about his nomadic childhood of sexual abuse, hustling and desperate search for love. Albert claims here that the avatar was a natural extension of alternate selves she developed while phoning in to suicide hotlines, and later, paying the rent as a phone-sex worker, adept at role-play.

Dern comes on strong as Albert, part hippie, part punk, existing in a constant state of febrile excitement and dragging Geoff and Savannah along in her gabby wake. She’s already been working the JT ruse for some time when Savannah leaves home at 25 and moves to San Francisco in 2001. The “itty-bitty Southern rent boy,” as Laura describes JT, talks regularly to a therapist and gives phone interviews, but the budding author remains physically elusive. Frustrated that her artistic endeavors must remain anonymous while lesser talents gain attention, Laura seizes on the idea of having Savannah pose as JT in a Polaroid to run with an Interview magazine profile. And from that first image, a whole masquerade begins.

The script suggests that for Savannah, binding her chest in tight sports bras or bandages to disguise her curves is part of her gender-nonconforming self-exploration. But the writers show as much sustained interest in that aspect as does egomaniacal Laura.

Dern has played abrasive, slightly unhinged characters before without completely stifling their humanity, as in HBO’s sadly short-lived Enlightened. Even the sublimely awful Renata Klein, her character on Big Little Lies, had a well-camouflaged good side. But Laura Albert, as written here, is a seriously off-putting manipulator, insensitive to anyone else’s needs and prone to peevish resentment once Savannah takes to her role as JT and the world starts clamoring for more of her/him. Both Laura and Speedie, another persona she invents to play JT’s brash Brit publicist and friend, are insufferable. What’s more problematic, though, is that Laura is sidelined for much of the action in what should be her story.

Instead we get a half-hearted account of Savannah’s emotional crosscurrents as she becomes romantically involved with Sean (Kelvin Harrison Jr.) in San Francisco and with Kruger’s Eva in Paris during a promotional trip organized by JT’s French publisher. But hard-edged Eva is more interested in securing the film rights to JT’s novel Sarah than in forging any lasting connection.

When both Geoff and Savannah make it clear that the public deception has gone on long enough, and that JT needs to disappear back into the shadows, Laura pretends to agree. But the notoriety proves difficult for her to relinquish, even if it comes with the jealousy of being ostensibly a bystander, and their exposure is inevitable.

The whirl of the media circus coupled with the constant threat of being unmasked should instill some kind of tension in the drama. But Kelly’s film is curiously slack in structure, and somewhat repetitive as Savannah attempts to set boundaries and then continually extends them again. As beguiling a presence as Stewart is, she can’t breathe much dimension into the thinly drawn, passive character or pack poignancy into Savannah’s search for her complete self. The script also fails to dig deep into the public appetite — as well as that of Hollywood and the literary world —for stories of outsider reinvention. Courtney Love, who once mixed in JT LeRoy’s circle, appears briefly in an inconsequential role, but there’s nothing in any way incisive here about the cult of celebrity.

Kelly and Knoop seem to want to make the case that neither woman immersed herself in the elaborate hoax purely for fame or financial gain, but more as a way of escaping the confining boxes of female identity. That may well be, but there’s little in this bland movie to back up such a feminist viewpoint. Ultimately, it just plays like a prank that spiraled out of control, which doesn’t make for a very involving story.

Cast: Kristen Stewart, Laura Dern, Kelvin Harrison Jr., Courtney Love, James Jagger, Dave Brown, Jim Sturgess, Diane Kruger
Production companies: Ray and Molly, LBI Entertainment, Thirty Three Productions, Sobini Films, in association with Buffalo Gal Pictures, Aquarius Content, Fortitude International, Ball and Chain Productions, Crosby Street Films, Black Bicycle Entertainment, Black Leather Jacket

Director: Justin Kelly
Screenwriters: Justin Kelly, Savannah Knoop
Based on Knoop’s book
Girl Boy Girl: How I Became JT LeRoy
Producers: Patrick Walmsley, Julie Yorn, Thor Bradwell, Gary Pearl, Cassian Elwes, Giri Tharan, Mark Amin, Dave Hansen
Executive producers: Justin Kelly Savannah Knoop, Phyllis Laing, Devan Towers, Anders Erden, Simon Williams, Wayne Marc Godfrey, Robert Jones, Cami Winikoff, Tyler Boehm, Jed Root, Tracy Christian, Nadine De Barros, Erika Olde, Margot Hand
Director of photography: Bobby Bukowski
Production designer: Jean-Andre Carriere
Costume designer: Avery Plewes
Music: Tim Kvasnosky
Editor: Aaron I. Butler
Casting: Jim Heber
Sales: Elevated Film Sales, CAA, Fortitude International
Venue: Toronto Film Festival (Gala Presentations)

108 minutes