A woman wanted a child badly enough to invent one. For the better part of a year, Eleonor Alejandra Marín Mendoza carried a pregnancy that existed only as performance — the swelling under her clothes, the talk of ultrasounds, the due date circled, the name already chosen. Her husband believed her. His family counted the weeks. Friends began planning a shower. Everyone around her was watching a pregnancy, and there was no pregnancy. Then the story reached the point every lie of that scale eventually reaches: it needed a body. She walked into the hospital where she worked, and she walked out with a newborn who belonged to another woman.

A Child of My Own could have been the coldest kind of true crime, and for a moment you brace for exactly that. Maite Alberdi has other plans. The Chilean director — twice nominated for the Academy Award, for The Mole Agent and The Eternal Memory — takes the Mexican case that once detonated into national scandal and refuses the shape true crime would force onto it. Her film is a docu-fiction hybrid, and its gaze stays gentle on a woman the press had already convicted. The question it chases is not whether Ale did it; everyone knows she did. The question is who assembles the pressure that makes a person fake a pregnancy in the first place, and keep faking it, past every chance to stop, until there is a baby in the wrong arms.

The film shows its method in its opening minutes, and the method is the argument. Alberdi puts herself on camera and auditions actresses to play Ale, the real woman’s recorded voice threading beneath the tryouts. It is a disarming way to open — a documentary admitting, before anything else, that it is about to build a version of a person. Ana Celeste Montalvo Peña wins the role. Armando Espitia plays Arturo, the husband who never suspected. Once the casting is settled, the picture divides into two registers that spend the next hour and a half arguing with each other.

One register is the reenactment, and it is bright, saturated, almost defiantly storybook. Cinematographer Sergio Armstrong lights the fabricated pregnancy the way Ale needed to believe in it — warm, hopeful, a life going right for once. The other register is the record itself: crackling home video, hospital security footage, the grainy evidence that resists being made lovely. Alberdi cuts one against the other so the seam always shows. You are never allowed to lose track of which images are the dream Ale built and which are the consequence she could not control. The prettiness is not decoration; it is the argument, staged from inside her wanting.

About halfway through, the artifice thins and the performers step aside. The real people arrive: Alejandra herself, Arturo, and the lawyers and psychologists who tried, at the time, to account for what she had done. The interviews are where the film does its quietest and most serious work. Contradictions surface in Ale’s own telling — a timeline that does not quite hold, justifications that shift as she speaks — and Alberdi lets them stand without withdrawing the sympathy she has spent an hour building. She has staged nonfiction before, but here she breaks the fourth wall more insistently than she did in The Mole Agent. Every Ale on the screen, including the tender one you have been watching, is a version somebody chose to construct — this film included.

It helps to know where Alberdi is standing. Her earlier documentaries turned observation into something close to fiction’s intimacy: an elderly man going undercover in a care home in The Mole Agent, a marriage dissolving into forgetting in The Eternal Memory. She is not a true-crime director borrowing prestige for a weekend. She is a nonfiction filmmaker who has always been interested in performance as a thing people do to survive. A Child of My Own belongs beside the recent wave of portraits of women driven to elaborate deception, the dramatizations that ask you to understand rather than gawk — but Alberdi pushes past most of them by refusing to let even her own reconstruction off the hook.

The case is unmistakably Mexican, rooted in a scandal that broke in 2009, but the pressure behind it is not confined to one country. Marín Mendoza wanted to be a mother, endured miscarriages, and lived inside a family and a wider culture that still take the measure of a woman by the child she can produce. The stolen newborn is the part that gets a person arrested and a headline written. It is not, in Alberdi’s hands, the story. The story is everything upstream — the wanting, the shame, the small daily performance a woman gives long before there is any crime to perform. By the time the theft arrives, the film has shown you how many smaller lies had to be believed, by everyone around her, to make the large one possible.

The mechanics of how it held for so long are their own kind of horror, and the film treats them with patience. A faked pregnancy is not one lie but a maintenance schedule of them: appointments described and never attended, a body explained away, a due date that has to keep advancing. Ale kept the fiction running until biology could no longer be improvised, and the only way to produce the promised child was to take one. When the newborn’s absence was noticed at the Hospital General de México, the machinery she had sustained for a year came apart in hours. Alberdi is less interested in the arrest than in the exhausting labor of belief that came before it — the daily effort of being watched as someone you are not.

There is something pointed about where this lands. Alberdi’s continuing relationship with Netflix puts a formally restless, morally unresolved documentary — one built on staged reconstruction and ruptured fourth walls — in front of the same mass audience the platform usually feeds a tidier product. The marketing can file it near true crime. The film argues against that shelf from the inside, every time it lets Ale be a person rather than a case, every time it reminds you that the sympathetic image was a choice and not a verdict.

That is the friction the documentary declines to resolve. A court long ago settled what Ale did and what it cost. What Alberdi reopens is quieter and harder: whether Ale was ever allowed to want a child honestly, in a life that treated her longing as an obligation — and whether a camera that restages, softens and openly casts its subject can hold her truthfully, or only tells one more flattering story on her behalf. The film knows it is implicated in its own question. That is why it starts with an audition.

A Child of My Own had its world premiere at the Berlin Film Festival, where it screened as a Special presentation. It reaches Netflix on August 13, accompanied by a limited theatrical run in the United States, the United Kingdom and Mexico, and runs 96 minutes. Gato Grande produced, with Sergio Armstrong on cinematography and Carolina Siraqyan editing.