It was raining and she was on her motorcycle. So she stopped and ducked into a Parisian boite for a drink to wait it out. “L’etoile d’Or,” it was called.

She noticed the birthday party, the candles-covered cake at the table across the way. The guy the cake was for checked her out, something else she noticed.

Beautiful young women perfected their makeup in the bathroom, their off-the-shoulders dresses drawing the eye. A couple of Chinese coeds sharing her booth took selfies.

Then — gunshots, screams, pleas, bodies and blood. “From the moment I saw people die, it’s gone,” Mia tells anyone who asks (in French, with English subtitles). The details of the trauma of that night are lost, unless others who were there can help her reconstruct them.

Alice Winocour’s “Revoir Paris” (Paris Memory) is a moving, understated journey into survivor’s guilt, a film whose characters keep their big emotions to themselves. Built on a quietly compelling performance by Virginie Efira (“Benedetta,” “Elle”), it may be the best depiction of how trauma changes your psyche and your life since the Peter Weir Jeff Bridges/Rosie Perez drama “Fearless.”

Months after the mass shooting, Mia is recovering from her physical wound and even asking about plastic surgery on her abdominal scar “to make it go away.” It’s not just the scar she’s talking about.

A Russian translator for French radio, she’s been unable to go back to work. A siren, candles, off-the-shoulder dresses, all sorts of things trigger her.

Her longtime love Vincent (Grégoire Colin), an always-on-call doctor, is no comfort. When we learn she moved out of their flat for months after the assault, we’re not surprised. They were having dinner earlier and he dashed out for yet another “emergency.” He wasn’t there.

Vincent doesn’t know what to say. Friends and family treat her guardedly, “like I’m some kind of ‘attraction.'” Mia is adrift, lost.

But when something draws her back to the re-opened L’etoile d’Or (The Gold Star), she finds some sense of direction. The manager doesn’t recognize her, just the haunted look in her eyes. There’s a support group “for people like you.” It meets there. The restaurant closes for them when they do.

Mia will meet Sara (Maya Sansa), the fellow survivor who organized the group. She will learn about online message boards and group chats for people trying to reconstruct that night in their minds, or to learn about how loved ones spent their last hour.

Teenaged Felicia (Nastya Golubeva Carax), who lost her parents that night, will reach out. So will the now-badly-injured Thomas (Benoît Magimel), the birthday boy who checked Mia out for blowing out his candles.

Not everyone will be glad to see her. But at least, with their help, she’ll start to figure out what happened and how she responded to a mass shooting and siege that forever changed her life and the lives of all who survived, and the survivors of those who didn’t.

Wincour — “Proxima” and “Augustine” were hers — gently leads us on a sometimes predictable journey into the after-effects of trauma and the “purpose” that turns into a near obsession for Mia.

It’s a film without extremes of emotion, a sanguine story told with a French reserve that Hollywood would have to adorn with more flash. It’s a mystery. She’s tracking down people she remembers from that night and hunches she had going into it.

But there are no explosive moments, just tenderly moving ones — a child in the Orangerie, the last museum her parents visited to see Monet’s water lilies, a wife’s recognition that something awful that she did not experience with her husband will end her marriage, guilt growing or receding, depending on what one finds out about others and oneself and how each responded to this crisis.

Winocour doesn’t waste screen time on the machine-gunning murderer, his motives, the media coverage or therapy sessions that some must have subjected themselves to.

We hear and see testimonials from people Mia meets, and those she never meets, about what they remember about what they did and how they’ve responded to that nightmare.

And it’s all handled with care and great craftsmanship by Winocour and her team — never a slack moment, never feeling rushed, either.

Big scenes are typically what burn themselves into our memories of movies. I remember Jeff Bridges grabbing a tool box, slapping it into Rosie Perez’s seatbelted-lap, and driving them into a wall to convince her that no, she couldn’t have saved her baby in that airplane crash in 1993’s “Fearless.”

What I think I’ll remember from “Revoir Paris” is the empty feeling that only “knowing” what your memory has lost can fill, and how well-acted and sensitively directed this immersion in coming out of the other side of grief can be.

Rating: unrated, violence

Cast: Virginie Efira, Benoît Magimel, Grégoire Colin, Maya Sansa and Nastya Golubeva Carax

Credits: Directed by Alice Winocour, scripted by Alice Winocour, Marcia Romano and Jean-Stéphane Bron. A Music Box release.

Running time: 1:45