Watch HDToday. A swan song for the factory age. Every autumn, a South America-bound colony of Vaux’s Swifts numbering in the tens of thousands enjoy a layover in a Portland, Oregon elementary school chimney. Sunset brings a vortex of swirling shapes, whose each tiny piece combines to form a hypnotic, ever-changing pattern; an equinoctial rhythm beats in every swoop of the organic overhead spiral. The defunct industrial chimney is our own demise, and yet the relentless, fluid choreography of the tiny migrants signals a new start, the turning wheel.