“Madeleine Collins” is an utterly fascinating spin on the “He/She’s living a double life” dramatic trope, and another fine showcase for the wonderful French actress Virginie Efira, of “Revoir Paris” and “Benedetta.”

Her character in this Antoine Barraud drama is a translator splitting her time between France and Switzerland. Her job has her constantly traveling all over Europe, turning negotiations in English, Spanish or whatever into French.

It’s nothing for her to say “I have to go to Spain” or “Warsaw” for a while. Her husband thinks nothing of it.

But “Judith,” (or is it “Margot?”) seems to have two of those, along with two names. Melvin is a French classical music conductor (Bruno Salomone), father to their two sons — a tween and a teen. Abdel (Quim Gutiérrez) is an unempoloyed Swiss hunk, father to little Ninon (Loïse Benguerel), a four year-old who pouts when Mommy can’t read her a bedtime story or show up for her first-ever dance class.

The viewer is instantly filled with questions. Wait…how did she…? How did he not…? And how does this tie into the opening scene, a young woman (Mona Walravens) who has an “accident” while shopping?

We’re about to find out, and none too quickly. Because Judith and Margot are going to have a hard time keeping these lives separate. The world she travels in is professional class, and there are sure to be accidental overlaps. There are too many people involved — her nosy teen and a judgmental, pushy Mom (Jacqueline Bisset) among them.

And those men in her life? How are they blind to all this, or “Ok” with it if they know? If indeed one or both of them do?

Efira lets us almost empathize as we watch our anti-heroine misstep, or get tripped up by circumstances. We see the wheels turning as she tries to keep these two separate “worlds” from colliding, the lies upon lies, the constant ducking out of a meeting, dinner or “family time” to take a call — outdoors.

“I need someone to be with me all the time,” Abdel complains (in French with English subtitles). “Let’s look at new houses,” Melvin suggests for her next stretch “at home.”

There’s so much to keep straight, which name she ordered that snowglobe from that city she was supposed to have visited under, which name to give to a stranger who flirts?

Because she is blonde and beautiful, and even the sketchy guy she secures fake IDs from (Nadav Lapid) is smitten.

Efira’s ability to play manipulative and nurturing, cunning and hurt, selfishly deceitful and vulnerable is impressive, and utterly necessary for the twists this script (by Barraud and Héléna Klotz) serves up.

Because “Madeleine Collins” doesn’t surrender her secrets easily, and by the end (a bit of a let-down), when we’ve figured it all out, we wouldn’t have it any other way.

Rating: unrated, sexual situations

Cast: Virginie Efira, Quim Gutiérrez, Bruno Salomone, Jacqueline Bisset, François Rostain and Mona Walravens

Credits: Directed by Antoine Barraud, scripted by Héléna Klotz and Antoine Barraud. Greenwich Entertainment release.

Running time: 1:46