Boundless ambition is nothing new at the movies, of course. But occasionally, a project can still come along with the scope and chutzpah to throw the audience for a loop. Human Flow, the staggeringly gargantuan look at the global refugee crisis from Chinese director and activist Ai Weiwei, takes a subject that could consume a documentarian’s entire career and seemingly attempts to get it all in one go. While the constant stream of jaw-dropping imagery can sometimes feel like a case of Too Much Information, the sheer macro power of the visuals packs a wallop.

Shot in more than 20 countries, and utilizing more than 200 crew members (how did the drone cameras not block out the sun?), Ai’s mammoth passion project travels between overpopulated crisis points around the world, pausing only briefly for interviews with refugees and aid workers. The Google Earth-style views of huge masses of people on the move never stop being absolutely dumbfounding.

Before turning to film, Ai initially made his name as an artist, and if Human Flow has a sticking point, it may be that his remarkable eye is sometimes just, well, a bit too remarkable for the subject matter. Some of the close-ups, in particular, have an oddly staged quality that threatens to diminish the reality of the situations. (The images are consistently gorgeous, even when maybe they shouldn’t be.)

Still, the artistic indulgences seem like small potatoes compared to the size of the filmmaker’s overall achievement—especially when considering the stories and sights he uncovers along the way, such as the stoic man who breaks down while recollecting how many of his friends have died at sea, or the shuddery, hard-to-fathom glimpses of a Lebanese refugee camp with approximately 100,000 people living in one square kilometer. “Without memory, you are nothing,” says one interviewee. What’s seen here will long be remembered. recommended