The river takes the lead: a low, steady pulse beneath rubber soles and the soft clink of glasses. On this Halloween night the Danube plays an old part with a new costume—city lights cutting glass-blue shapes across the water, bridges lit like stage props, and the Hungarian Parliament’s Gothic façade throwing its carved face into the dark. You step onto a mid-sized cruise vessel at Vigadó tér as a cool wind pushes upriver toward Margaret Island; a DJ threads chilling beats with pop, bartenders hand over seasonal cocktails, and the city—usually indifferent by day—seems intent on being seen.