Jim Allison, left, with Tasuku Honjo, receiving the Nobel Prize for medicine in 2018. Allison is the subject of the documentary “Jim Allison: Breakthrough.” (Uncommon Productions/Dada Films)
Movie critic

Rating: (4 stars)

At the movies right now, you can see Brad Pitt expertly deploy his laserlike blue-eyed focus as an intrepid astronaut; Sylvester Stallone fret and flex his way through another “Rambo” iteration, and the gentlemen of “Downton Abbey” make sophistication sexy again.

But they all pale compared with this season’s hottest new screen hero. Jim Allison, the brilliant, stubborn, down-to-earth and hopelessly lovable title character of “Jim Allison: Breakthrough,” may not initially look the part of a superman. But by the end of this absorbing, gracefully constructed and deeply moving documentary, he will have audiences wanting to join the fan club and get the T-shirt. This is a “just see it” movie, as in: Forget flowery language, redundant synopsis, clever paraphrasing or hyperbolic praise. Just see the dang thing.

Cancer researcher Jim Allison is the subject of the documentary “Jim Allison: Breakthrough. (LeAnn Muelle/Uncommon Productions/Dada Films)

But in case synopsis is needed: We meet Allison as he is receiving the Nobel Prize for medicine in 2018, the long-haired, bespectacled scientist looking pleased and just a tad bewildered. “Breakthrough” then takes us to tiny Alice, Tex., where Allison grew up and had the temerity to challenge creationism in his public school. After enrolling in the University of Texas at Austin, he began to study biology and perfect two notable talents: novel and meticulous lab research and harmonica playing at beer-soaked blues joints.

Just how this path led to the Nobel is part of the story of “Breakthrough,” but it doesn’t begin to sum up what turns into a captivating homage to scientific discovery and an endearing portrait of a modest, quietly driven genius. Directed with humanity and acute insight by Bill Haney (“The Price of Sugar,” “The Last Mountain”), the film reveals the profound emotional loss that motivated Allison’s work, which eventually began to concentrate on immunotherapy as a treatment for cancer. The real, life-or-death and very human stakes of Allison’s obsession are never far from sight in a film that carries viewers along on a dramatic personal and professional journey that involves heartbreak, grief, perseverance and — improbably — a love story for the ages. Allison’s often improbable life story is given just the right doses of twangy levity by narrator Woody Harrelson, one of several wise choices Haney makes throughout the film.

And “improbable” is the right word: We haven’t even gotten to Willie Nelson.

At a time when science is increasingly politicized and the notion of objective reality itself is under attack; when students are told to go into STEM with little or no idea of how cool it can be; when people wake up every day wondering where hope can possibly be found, “Jim Allison: Breakthrough” offers an inspiring and heartening retort. Check it out. Take the kids. Go twice. Just see the dang thing. You won’t regret it, and you’ll never forget it.

Unrated.  At Landmark’s E Street Cinema and ArcLight Bethesda. Contains some adult themes. 90 minutes.