The bur­rito can­nons blared at noon, and into the sky above the city a fusil­lade of foil tubes went sailing: carnitas, carne asada, veggie supreme. They traced high glinting parabolas, hanging per­fectly still at the apex, then accel­er­ating earth­ward until their napkin-parachutes deployed. Pedes­trians turned, arms outstretched.