This week’s Op-Doc is “The Diver,” by Esteban Arrangoiz. Part four in “A Moment in Mexico,” our special six-part series of Op-Docs by Mexican directors, “The Diver” profiles a man who has found long lasting contentment in a dirty job: diving into the sewers and water treatment plants of Mexico City to clear blockages and reduce the risk of floods. As Arrangoiz writes, “Mexico is undergoing multiple crises: humanitarian, corruption, garbage. This film shows us how through his work, a human being is capable of finding beauty, pleasure and the essence of his humanity inside the detritus. This moves me, gives me hope and compels me to make movies. I think Mexico needs stories like these.”