I’m going to be honest. The idea of a documentary about a septuagenarian artist who creates mosaic murals around his Philadelphia neighborhood sets off my folksy-charm-dar AND my old-people-have-the-darndest-resigned-melancholia alert AND my early-ZZZZZ-detection warning system. But false alarm! False alarm, folks. Go about your business. In a Dream deserves none of those dismissals.

It begins as the story of the aforementioned eccentric artist Isaiah Zagar, living out his semi-idyllic twilight years with his tirelessly supportive wife Julia. The couple buy derelict buildings in Philadelphia (warehouses, apartment blocks) then Isaiah mosaics every surface with broken mirrors, fragments of pottery, bottles, bicycle wheels, junk. Julia looms immense in Isaiah’s work. He has done thousands of portraits of her, he says, some several stories tall. Her face is everywhere, and when he speaks of her and how she loves him it’s with a guileless, silly exuberance. “He can’t function, you know, too well in this world. He’s kind of a rare flower. A thistle, maybe,” Julia says. “I was his reality base, and he was my bird. He flew around.”

Documentaries made by family members (In a Dream was filmed by Isaiah and Julia’s son, Jeremiah) can suffer from a toothless idealism—glossing over the rough patches. But in this case, the familial intimacy makes the film. About halfway through, Julia notes that Isaiah is becoming more and more detached from actual life. Then, almost off-hand, at a coffee shop, Isaiah mentions on camera that he’s having an affair and the film transforms into the disintegration of a love—one that is physically manifested all over Philadelphia. The camera is there when the Zagars pick up their older son from rehab, as he senses something is wrong, as they attempt to talk around the elephant in the room. It’s there when Julia releases her rage in a frightening screech; and when Isaiah later does the same, realizing he just lost everything. It’s exhilarating and very, very sad.