“We were just so struck by how willingly these scientists were saying this was a huge deal,” says director Adam Bolt. He had worked on science stories in the past and was used to hearing more hedging. “It quickly became clear that, to them, this was one of the biggest breakthroughs in biology ever.”

Bolt decided that a movie about Crispr deserved breaking with some conventional wisdom about how science is captured on film. He didn’t want to make a project that speaks to audiences at a fifth-grade learning level. Instead, he pushes deep into the nitty-gritty of how the technology actually works, with the help of glittering animations that feel like they actually surround the viewer. While little of this information will be surprising to people who’ve heard of Crispr, these sophisticated renderings offer a new layer of understanding to all but the most wizened gene editor. “We wanted it to feel like you’ve been shrunk down inside a cell and seeing it happen in front of your own eyes,” says Bolt.

Scientists have been pursuing Crispr since 2012 in the hope that it can be used to cure a number of genetic diseases, including sickle cell anemia. (Human Nature is dedicated to the memory of Shakir Cannon, a crusading sickle cell patient advocate who hoped to live to see the day Crispr would cure his disease. WIRED profiled Cannon in 2018, shortly after he passed away.) But it also offers possibilities for treating a multitude of inherited genetic conditions, cancer, and infectious diseases like HIV.

Human Nature lays out these tantalizing possibilities alongside some even more far-out applications, like Crispr-ing pigs to grow human organs. Then viewers spend time with Steven Hsu, the chief scientific officer at Genomic Prediction, a company that generates genetic scorecards for prospective parents’ IVF embryos. Hsu believes that using Crispr to create children free of disease will one day be routine, and that parents who leave their genetic recombination up to chance will be the ones deemed unethical by societies of the future.

Which is why audiences might feel let down by how Human Nature handles the birth of the world’s first Crispr-edited humans. The film was nearly finished in November 2018 when one of the movie’s subjects–MIT Technology Review reporter Antonio Regalado–broke the news that a Chinese scientist had used Crispr to edit human embryos in an attempt to make them immune to HIV. After it emerged that the scientist had crossed ethical lines to obtain consent from the babies’ parents, and had broken Chinese law to perform the editing itself, the researcher was sentenced to three years in jail. Further revelations about the poor quality of the editing revealed that the resulting children likely will not have resistance to HIV.

After spending the first hour of the movie building up the possibility that Crispr could be used to design future generations of children, and probing the ethical implications of doing so, the brief and sudden arrival of this much-anticipated outcome is jarring. The movie flashes a few slides showing relevant news stories before moving on to the future of Crispr technology, without dwelling on whether the rogue experiment will be a one-off or an inflection point in the history of gene editing. If you were hoping for a Crispr Baby expose, this film is not it.

Asked about why the filmmakers didn’t take more time to refocus the documentary, Bolt says that they were worried they wouldn’t be able to do justice to such a complex story and that there were many things wrong with the experiment that didn’t have to do with the fundamental question they were exploring with the film: Whether or not scientists should make permanent changes to the human gene pool. While Bolt has questioned that decision in the intervening years as they brought the documentary to the end of production, ultimately, he says, he’s glad they didn’t try to rush something through. “At the end of the day, we still accomplished what we set out to do,” says Bolt, “which was to make a film that people will walk away from feeling like they understand Crispr and what the ethical questions are around its use.”