I’m standing on cracked asphalt by a high security fence at the eastern edge of Ireland. The sky is cold pewter, the salt wind bitter. I’ve come all the way here to watch wildlife, and I have just turned my back on the only birds I can see. The miles of sand behind me have been washed by the Irish Sea into a perfect blankness, pearled with gulls and flocks of migrant waders. It’s beautiful. But my friends Hilary and Eamonn have told me to look instead at Dublin’s Poolbeg Power Station, a giant’s play set of brutal turbine halls facing the shining sands. Set amid sewerage works, derelict red-brick buildings, wharves, cranes and shipping containers, this is a bizarre spot for a wildlife pilgrimage. Two decommissioned cooling chimneys tower above us, marked with vertical washes of rust and horizontal bands of red and white. Rising from the horizon, they are your first sight of Ireland if you arrive from the east by sea and the last when you leave. Visible throughout the city, they have come to mean home for a whole generation of Dubliners — and for the peregrine falcons that have nested on them for years.

For a while, not much happens. We watch flocks of pigeons clattering about the roofline in shadowless winter light. My face grows numb with cold. I shiver. Then, below the chimneys, a pigeon cartwheels like a thrown firework through a broken window into the darkness beyond. There is something horrible about its descent. Had it been shot? Had some kind of fit? It takes me a bit to work out that the pigeon was trying to get inside as fast as possible, and then I know that the falcons have come.

A narrow black anchor appears suddenly, falling fast toward the west chimney as if on an invisible zip wire. Seeing something alive descending to earth at such speed brings a hitch to my throat. A faint, echoing call drifts toward us, the unlikely ee-chip ee-chip of a swinging, unoiled door. It is the male, the tiercel. He swerves, spreads his wings wide to brake and alights upon the rail by a nest box fixed by a worker to a metal walkway a hundred feet above. He shakes his feathers into place and sits looking toward the estuary, flat-headed, an inverted bullet-­shape black against the sky.

“Do you want to see?” Eamonn says while gesturing to a telescope. Through the device, the falcon is oddly two-dimensional, rippling in the bright circle as if seen through water, and my eyes ache as I try to focus on small points of sharpness: the barred feathers of his chest, his black hood, a faint chromatic fringe ghosting him with suggestions of dust and rainbows. He’s exquisite, the color of smoke, paper and wet ash. He starts preening his feathers; he puffs out his belly, half closes his eyes, angles his head back to zip single scapulars through his neat, curved beak. Gusts of wind rising up the chimney face blow his feathers the wrong way. His talons are curled around rusting steel. The wind has ice in it. He looks utterly at home.