It's a cloudy late August afternoon on the banks of the Thames Estuary near Benfleet in Essex. Wild gusts of wind race in over the water. On this side, spots of rain float in the air but a mile away on Canvey Island there's sun. It's low tide. Birds swoop and swirl over the exposed mudflats, hunting for food. Redshanks, gulls, little egrets, oyster catchers, curlew, avocet, crows. We climb down onto the mud and leave the microphones beside a tall upright rock for some shelter. It's not unlike a standing stone. The traffic on Canvey Island is a distant rumble, punctuated by the occasional motorbike. From behind, an aircraft takes off from Southend Airport flying directly overhead, tearing the sky, then out over the estuary. The wind drops and a blissful peace returns. Feathery wings swoosh nearby. Trains pass softly on the London Tilbury Southend railway line. Mud bubbles and pops in the quiet, sparkling with the movements of tiny creatures enlivened by the drying air.