Activist Elvira Madrid is skeptical of politics, but is helping shape Mexico City’s legal shifts on sex work. La Merced, in downtown Mexico City, is one of the country’s biggest and oldest retail markets. And the world’s oldest profession also thrives there. To the sides of the labyrinth of passageways that run along the market stalls selling, well, everything, stand women of all ages and sizes. Many of them play with their phones as they wait for their clients, leaning against the shops behind them to take the weight off their high-heeled feet. The street of Corregidora, in the heart of la Merced, is home to la Brigada Callejera, which means Street Brigade. A collective dedicated to fighting for the rights of the country’s sex workers, it was formed nearly 20 years ago by Elvira Madrid because some 3,500 of the city’s estimated 7,000 sex workers are based here. Flitting through a barred door and then through a dank, dark corridor and up a few flights of stairs leads one to La Brigada’s brightly painted office. | 
