Just as comely young Barcelona couple Alexandra (Natalia Tena) and Sergi (David Verdaguer) resolve to start a family together, she scores a fellowship for a year in L.A. After some tensely intimate deliberation — the movie’s opening shot lasts 23 minutes — they agree it’s an opportunity she can’t miss. But wasn’t that other plan an opportunity, too? So begins filmmaker Carlos Marques-Marcet’s potent two-hander, a casual but committed study of long-distance relationships in the digital age. The material is well-controlled but not overworked: In that one-take overture, it’s important that a single scene can accommodate both sexual passion and the pointed silence of toast being munched in a cloud of regret. The eventual first cut is meant to punctuate the shock and upheaval of the couple’s separation, but before that there’s also the establishment of a wary attitude about the technology of human connection; it’s in the way we see their drowsy post-coital bliss intruded upon by the insidious urgency of an email, good news though it is. What follows is the full array of technical communications difficulties. Marques-Marcet hasn’t reinvented the wheel of modern relationship drama — Joe Swanberg and Greta Gerwig covered similar ground in 2008’s Nights and Weekends, to take one example — but the familiarity of his scenario is why we invest. What’s more, it’s dramatized in cinematic, contemporary-seeming ways, with players who are authentic and beautifully specific. From experience, we can’t help but worry for them — and hope against hope that their future together somehow will work out.