Alain Cavalier’s “Le combat dans l’île” is the wrong length. At 104 minutes, the estimable 1962 French New Wave drama sizzles with the intrigue of a mystery and the urgency of a political thriller, but still maturely plumbs the romantic entanglements of a complex love triangle. Centering on an assassination attempt, the movie is packed with a cornucopia of disparate elements, including union strife, an international manhunt, illness, a theater production and a vengeful duel. Reportedly intended as an indictment of French right-wing fervency in the early 1960s, “Le combat dans l’île” works just as well, if not better, when it is simply the compelling story about the mysterious inflections of the heart. It’s audacious filmmaking for a debut film. But Cavalier would have been well served to give his feature some slack. I’m not a fan of films padding extraneously, but “Le combat” could have easily added half an hour without trying a viewer’s patience — the three engaging main characters are intriguing enough to warrant deeper inspection and the events which embroil them are amply sturdy and significant to support more penetrating scrutiny.

With eyebrows like a swan’s unfurled wings, Romy Schneider plays the restless Anne, a bored Parisian housewife in her early 20s, with a coquettish flourish. (Schneider, who was on her way at the age of 24 to forging a reputation as one of Europe’s most coveted actresses, possesses a seductive allure which suggests Simone Signoret’s younger sister.) Anne has been married for just a few years to Clément, a cinched-up, dour, industrialist’s son just a tad older than her who quits the family business to covertly scheme for a violent anti-communist, anti-democratic extremist group. Jean-Louis Trintignant portrays Clément with his signature placid, inscrutable face (which he’d use to magnificent effect later in the decade as The Examining Magistrate in 1969’s “Z”).

When the couple does venture out to places which enthrall Anne, like smoky jazz clubs, the former actress is back in her element while hubby seethes. A bubbly persona with a penchant for champagne, her flirting may be inconsiderate but his reaction is brutish; Clément treats governments and love interests by a single authoritarian mantra: “power must be seized.”

The film provides no back story to their relationship, so it’s hard to imagine how they met. Yet Schneider and Trintignant are such strong presences that they intensely convey the way seemingly mismatched couples can become concatenated. This ill-fitting union possesses its own personal kinesis so that even steely eyes can seduce. But those seductive moments are fleeting.

Anne may be looking for excitement, but a search of a hallway closet unearths an entirely unexpected discovery, a carefully-wrapped bazooka. Clément passes off the weapon’s importance; Anne seems less distressed by the munitions than the fact that despite the sparing moments of consuming passion, her husband is a dud. Soon after, Clément carries out a heinous, politically-motivated terrorist act.

Fleeing from Paris after his nefarious crime, the couple hide out at the country house of Clément’s childhood friend, Paul (Henri Serre, fresh from his role as Jim in “Jules et Jim”), who knows nothing of Clément’s actions. (Anne doesn’t make any connection either.) A young widower, Paul is a printer immersed in a bucolic life with a friendly, grounded disposition as warm as the fisherman’s cable knit sweaters he favors. With his round eyes, pronounced nose and full lips, Paul has the oversized features of a sculptor’s model. Expressive without being flamboyant, Paul is the political and physical antithesis of his distant chum. As the three linger after dinner on the first evening listening to the radio, Cavalier delivers a clever and riveting scene as the targeted politician reveals to a national audience a double cross among the perpetrators by playing a surreptitious tape recording; this is where the full extent of Clément’s barbarity is revealed to Anne.

Found out, Clément dashes off to South America alone, but not before he is unequivocally condemned by his childhood friend; Anne, though, is still, strangely, emotionally entangled. As Anne and Paul remain and begin their own relationship, “Le combat” takes on a hurried pace. The gestation of the new romance feels comparatively rushed to the earlier sequences. Like the untold history of Anne and Clément, Paul’s past is touched upon but not examined to the depth that a film as robust as “Le combat” could have handled. (Clément’s journey to the Americas is told in a few solitary images.) The film is interspersed throughout with quickly shown images, almost like photographs, with the camera shuttering brief, enigmatic glimpses. It’s an interesting technique but with so much happening to the new couple – including Anne falling ill, the two of them moving to Paris, Paul setting up a print shop, Anne reborn as an actress with the unveiling of a new play, and a quietly intense roundtrip drive out of the country for a decidedly private matter – these snippets seems incidental. The condensed movie could have prospered from more detail and exposition being focused on these challenging and instrumental episodes.

“Le combat” is bolstered by the evocative black and white cinematography of Pierre Lhomme. Scenes in both the urban settings and the countryside are shot through diffused light, as though set in misty daybreak or dusky sunset. Lhomme wonderfully incorporates shadows throughout the film, but especially effectively in the Parisian milieu.

When Clément returns, one act of revenge in Argentina has hardly sated his lust for retribution. With his skewed sense of honor as the focal point, the plot takes on a vibe that you believe will submerge the film in noir fatalism. Cavalier’s first directorial effort avoids this fate but concludes with a melodramatic climax and a lingering sensation that a very fine film could have been richer still with another reel on the projector.