If modern viewers have heard of Jean Seberg, it’s likely from her star-making turn in Jean-Luc Godard’s Breathless (1960), but it’s her political interests that intrigue the makers of Seberg, who fail to justify the existence of a biopic with such a focal point.

As Jean, Kristen Stewart is again out of her dramatic depth, leading a concerted effort of cringeworthy overacting by a fairly talented cast sorely lacking direction from Benedict Andrews, whose revered theater skills have yet to translate to the screen.

Written by the period-happy team of Joe Shrapnel and Anna Waterhouse (Race; The Aftermath), the film quickly steps on shaky ground when, after a brief airplane encounter with activist Hakim Jamal (Anthony Mackie), Jean disembarks and randomly joins him and his colleagues in a “Black Power” salute.

The rest of the film is similarly haphazard, slapping together twin narratives of Jean’s activist and romantic involvements with Hakim and efforts by FBI agents Solomon (Jack O’Connell, Unbroken) and Kowalski (Vince Vaughn, ending his dramatic winning streak) to expose her subversive doings.

Full of would-be riveting moral conundrums, Seberg strives to reveal the emotional and psychological toll the events take on Jean, Jamal, Solomon, and their partners — among them a mismanaged Zazie Beetz and Margaret Qualley — but instead devolves into cliché agent-with-a-conscience moments and clunky Conversation-like paranoia.

Instead of an inspirational, revealing film, meant to be a bombshell about government interference and the power of acting justly, Seberg simply fails to detonate.

Grade: C-minus. Rated R. Now playing at Carolina Cinemark

(Photo: Amazon Studios)