Advice to romantic couples: I know it seems romantic and exciting to pull a “Before Sunrise” and agree to meet that new flame at a prearranged time and place, but play it safe and exchange numbers. Get their email address. Share Google Calendars.

Otherwise it can lead to a lot of misunderstanding and confusion, and romantic melodrama in the case of “3 Hearts,” the well-acted but overwrought French film by director Benoit Jacquot (“Farewell My Queen”). The film, now out on Blu-ray from Cohen Media, throws a mountain of complications (some self-inflicted) between its couple, and amps up the stakes with enough ominous music and narration to make us wonder not only if they’ll stay together, but if they’ll survive. It’s like a soap opera as directed by Christopher Nolan.

Sylvie (Charlotte Gainsbourg) and Marc (Benoit Poolevorde) have both missed their train back to Paris. Meeting in a cafe, they end up walking and talking around town till dawn. It’s a strong scene, both actors suggesting the nervous thrill of making a connection when they least expect it to happen.

They make a plan to meet back in Paris, but are thwarted by circumstances. Plus, Sylvie is unhappily married, and decides to go with her husband to his new job in Minneapolis, which is depicted in the film as a sort of frozen purgatory. (Guys, it’s a really nice city!) Unsure what went wrong, Marc moves on, eventually starting a gentle courtship of one of his clients, Sophie (Chiara Mastroianni). They get married.

And it turns out Sophie is Sylvie’s sister.

For the first hour of “3 Hearts,” Marc is unaware of the connection, but we are, and Jacquot builds tension as he just misses seeing evidence here and there. In the second hour, Sylvie comes back to France, and the suspense comes from wondering whether Sophie will find out, and what Marc and Sylvie will do.

Jacquot squeezes every drop of melodrama out of his preposterous story, shooting “3 Hearts” as if it were a thriller, full of meaningful glances and sudden stings of music, the nervous Marc seeming less like the fulcrum of a love triangle than a guilty man trapped in a film noir.

The overhyped tone feels at odds with the relatively grounded performances, especially Gainsbourg as the cool but soulful Sylvie, and Mastroianni as the kind, devoted Sophie. The great Catherine Deneuve is also in there as their mother, but is given surprisingly little to do. I think we could have become invested in their stories without the histrionics.