Watching "Ai Weiwei: Never Sorry" is like experiencing a thrilling unfinished symphony. The story is enthralling, but it’s not over, and there’s no telling where it’s going. Which makes what’s on screen all the more involving.

Though he was named the most powerful artist in the world by ArtReview, Chinese provocateur and human rights activist Ai is simply a boldface name to most people, someone whose life and significance we are only vaguely aware of. Alison Klayman’s award-winning documentary definitively changes that.

A journalist based in Beijing, Klayman more or less stumbled on Ai and his story but ended up filming for two years, forging a personal connection and getting exceptional access to the artist and those closest to him.

Her film reveals him to be a man of piercing intelligence, charisma and fortitude who becomes increasingly impressive as more about him comes out.

‘AI WEIWEI: NEVER SORRY’ Rated: PG Opens today at Consolidated Kahala

Ai sprung onto the world scene as a conceptual artist who helped design the Bird’s Nest stadium for the Beijing Olympics in 2008 and then announced he was boycotting the Games because of what he saw as dictatorial government policies. He is, as a fellow artist says, "not the kind of person we are familiar with in China. He doesn’t work within the system. He’s just himself."

Being just himself has recently gotten Ai into extraordinary trouble with the Chinese regime. He was held incommunicado for 81 days last year under conditions that verged on psychological torture and was released only to be charged with tax evasion and fined $2.4 million in unpaid taxes and penalties, a sentence that was upheld last month.

"I am now more of a chess player than an artist, waiting for my opponent to make the next move," Ai says. Still, he refuses to back down. "If we don’t push, nothing happens. Life is more interesting when you make a little effort."

The Chinese government has gotten tough on Ai because social media, first a blog and then a Twitter stream (@aiww), has made his presence and his thoughts ubiquitous in China and beyond. "The Internet is the greatest invention of the 20th century," he says. "It allows ordinary people a chance to change public opinion."

Ai first became well known in China in the aftermath of the devastating 2008 earthquake in Sichuan province in which thousands of children died as a result of flimsy construction in state-built schools. The Chinese government refused to release specifics about the students who died, leading Ai to start the Sichuan Earthquake Names Project, which collected more than 5,000 names of victims.

Ai further memorialized the young people in a museum show in Munich, where he used 9,000 backpacks to spell out a one-sentence tribute to the students. As Evan Osnos, the New Yorker’s China correspondent explains in the film, the issue of transparency, of what should be made public, is one of Ai’s key issues. That stand has gotten Ai into all kinds of dire situations, including being beaten in a hotel room by police, an act we can hear on a tape the artist made. Compelled as always to push back, Ai files lawsuit after lawsuit against the government, because he believes the exercise will be as revealing as it is futile. "We want them," he says of his country’s officialdom, "to show their actual face."

One thing Klayman’s thorough reporting reveals is the likely influence of Ai’s late father, the respected poet Ai Qing, on his son. A passionate idealist who risked his life to support the Communist Party, the elder Ai ran afoul of the state during the Cultural Revolution and endured years of exile, beatings and humiliation. "It is an experience I cannot erase," the younger Ai says.

Another formative influence was the 12-year period, starting in 1983, that Ai lived and worked in New York City. He developed a passion for pastrami sandwiches — we see him stockpiling them during a visit to the Carnegie Deli — and for democracy. "Once you experience freedom," he says quietly, "It stays in your heart. No one can take it away."

All the time Klayman put in with Ai also leads to privileged glimpses of the private man, including conversations with his wife and fellow artist, Lu Qing, and glimpses of his life with a young son he had with another woman.

Perhaps most touching is an interchange with his mother, Gao Ying, who worries that her son "wants to solve the problems of the whole country." His response is a fatalistic "if they want to get me, they will." He is not fearless, he elaborates at another point, but quite fearful. "The danger is really there," he says, "but the danger is stronger if you don’t act." Ai walks that walk every day, and that’s what makes him, and this film, so impressive.