Brazilian filmmaker Marcelo Gomes was taking a taxi through Lisbon, where he did the post-production work on a recent film, when he fell into conversation with his driver, a surfer who lived in a busy apartment block in the Portuguese capital. Just a few years ago, the driver said, he knew everyone in the building by name. He held onto their spare keys. They rang his doorbell when they needed sugar.

But slowly, the building began to change. Now his neighbors were British, Italian and French. “Every day someone knocks on his door and says, ‘Do you want to sell your apartment?’” Gomes tells Variety. “And he says, ‘I’m going to resist, because Lisbon has to keep its soul.’”

The battle to preserve a proud city slowly being overwhelmed—and transformed—by the forces of mass tourism and gentrification is the backdrop of “Lisbon in the Backmirror,” the latest film from the acclaimed Brazilian director, which was presented as part of the Docs-in-Progress program of Cannes Docs during the Marché du Film Online. Currently in production, it’s slated for a late 2021 release. World sales are being handled by Philippa Kowarsky of Cinephil.

The free-flowing, wide-ranging conversations with Lisbon taxi drivers that form the backbone of the film span the three years Gomes has spent traveling to the city. A gregarious narrator and easy conversationalist, he has devoted much of his time while working on “Backmirror” to crisscrossing Lisbon by taxi and unearthing intimate details about his drivers’ lives.

He recalls arriving in the city to deserted streets on his first visit, unaware the day was a national holiday to celebrate the birth of the Portuguese poet Luís de Camões. As his driver discoursed on poetry and fado music, the city cast its spell. “Lisbon is very unique, because it’s very small, everybody knows everyone. People live a very provincial life,” says Gomes.

But while the director was seduced by what felt to him like “a hidden gem of European culture,” his driver described how the rising cost of living had pushed him to the city’s margins. Old ways of life were being wiped out. “These taxi drivers in Lisbon, they see the worst phase of this gentrification. That was the seed of the idea [for the film].”

With each cab ride across the changing city, the stories flowed. A long-serving taxi driver who teaches fado to Chinese tourists in her spare time. Another who inherited a taxi license from his father and hopes to pass it down to his own son, but worries that his livelihood will no longer be sustainable with the rise of ride-sharing apps like Uber. “Maybe he won’t want to do it,” says Gomes. “That’s the kind of tradition that’s finishing.”

Three years after his first visit, the ramshackle street with charming old houses where he once stayed is now buzzing with hostels and boutique hotels. “When you come back to Lisbon in five years, there will be no one who can speak Portuguese,” the director muses. But he also believes that the dramatic events of recent months can have a positive impact on the city, as the coronavirus pandemic has forced many people to rethink their relationships to the world around them.

“I think after the pandemic, people have reflected a lot about the neighborhood…how they have to build up the community, and [show] solidarity,” says Gomes. “It’s a good documentary that makes people reflect more about that.”