When it comes to filmmakers and actors taking chances, we have a tendency to serve up the superlative “brave” in an almost cavalier fashion at times.

It’s so brave for that comic to take on a dramatic role.

How brave of that actress who isn’t a supermodel to do a nude scene.

What a brave move for the studio to kill off that beloved superhero character.

In the case of writer-director Jennifer Fox and the HBO movie “The Tale,” to call the film “brave” is just the beginning. This is a courageous and lasting work about an adult survivor of childhood sexual abuse who is still coming to terms with the trauma some 35 years down the line. Few films have addressed this subject matter in such a powerful fashion.

An accomplished documentarian, Fox based this fictional film on her own experiences as the victim of sexual abuse when she was an adolescent.

In a performance that ranks among the best I’ve seen in any film (theatrical or otherwise) this decade, Laura Dern essentially stands in for Fox, playing … a documentary filmmaker named Jennifer, who uses her journalistic skills to investigate events from a summer 35 years in the past, when she was 13 years old and she was emotionally and physically abused by a 40-year-old man she had come to trust and admire and love.

Writer-director Fox allows the story to unwind with a perfect balance of flashbacks to Jennifer’s adolescence and present-day scenes of Jennifer coming to terms with the harsh reality of events, which aren’t completely in sync with the way she has been remembering things all these years.

(One example: when Jennifer initially takes us back to that summer, she is a girl of 15. Her mother corrects her about the timeline and says Jennifer was only 13. We return to the same scenes, only this time with a younger actress playing Jennifer.)

When we meet the 48-year-old Jennifer, she has a great career and a warm and loving relationship with her fiancé Martin (Common). If the past is weighing heavy on her mind, she does a great job of disguising it.

Then comes a phone call from Jennifer’s mother Nettie (Ellen Burstyn), who has come across a short story Jennifer wrote when she was 13 — a story clearly based on Jennifer’s real life, a story strongly suggesting she was raped on numerous occasions by her track coach.

Track coach Bill (Jason Ritter) wins the trust of 13-year-old Jenny (Isabelle Nelisse) in "The Tale."

Track coach Bill (Jason Ritter) wins the trust of 13-year-old Jenny (Isabelle Nelisse) in “The Tale.” | HBO

Jennifer is stunned. She has vague and gauzy recollections of a coming-of-age summer in which she bonded with the exotic and beautiful Mrs. G (Elizabeth Debicki), who operated a horseback riding camp, and a running coach named Bill (Jason Ritter), with whom Mrs. G was having an extramarital affair.

“It was something … beautiful,” the 13-year-old Jenny (Isabelle Nelisse) wrote of her relationship with Mrs. G and the handsome former Olympic double gold medal winner Bill.

No. It wasn’t. But we can understand how young Jenny would have felt that way.

As Jennifer recalls it, these two sophisticated, open-minded adults treated her as an equal and allowed her into their lives. (At times the adult Jennifer has a “conversation” with her younger self, in an effort to understand exactly what happened that summer.)

Eventually Jennifer comes to realize the dynamic was the polar opposite of beautiful. She reconnects with figures from that summer and essentially interrogates them about what happened. She re-examines her writings from the time. She has difficult and painful discussions with her mother, who is punishing herself for not following up on suspicions she had about Bill spending so much time with her daughter.

The scenes of Bill creepily seducing Jennifer in a series of carefully orchestrated moves are infuriating and horrific. Writer-director Fox refuses to take the comfortable route by only hinting at the physical abuse. (Adult body doubles were used for the rape scenes.) The moment when the adult Jennifer sees Bill (now played by John Heard) for the first time in 35 years is brutal and raw and uncompromising.

Ellen Burstyn co-stars as Jenny's guilt-ridden mother in "The Tale."

Ellen Burstyn co-stars as Jenny’s guilt-ridden mother in “The Tale.” | HBO

At 85, Ellen Burstyn remains a vibrant and singular presence. She is magnificent as Jennifer’s guilt-ridden mother. Kudos as well to Jason Ritter for playing the loathsome Bill so effectively; we believe Bill believes his own sick and twisted B.S. as he takes advantage of Jennifer.

What a remarkable performance by Laura Dern. It’s a beautifully nuanced portrayal of a smart, accomplished, independent woman who finds the courage and strength to confront the past — and to understand that the demons poking at her subconscious all this time were not of her own making.

The real demons were the monsters that took advantage of her.

★★★★

HBO presents a film written and directed by Jennifer Fox. Running time: 115 minutes. Premiering at 9 p.m. Saturday on HBO and available on HBO NOW and HBO GO.