Dave Meslin, a 47-year-old Canadian activist, is known for his campaigns to defend public space from commercial interests. For 15 years, he has been lobbying Toronto to remove illegal billboards from neighbourhoods across the city. He assembles a team of volunteers, including his 11-year-old niece, to gather intelligence and strategise on how to bring down the billboards. They are prepared to do whatever it takes to reclaim a local green space. As the Billboard Squad clashes with power, bureaucracy and inertia, Dave grapples with the emotional complexities of activism.