Julia is a phone operator in Mexico City who divides her time between her job, her daughter, and the danzón: a Cuban dance very popular in Mexico and Central America. Every Wednesday, Julia does the danzón with Carmelo in the old Salón Colonia. They've danced for years, but barely know each other. One night, Carmelo disappears without a trace. Feeling lonely and sad, Julia takes a train to Veracruz, where she knows Carmelo has a brother. The sudden trip will change Julia's life forever.