Night has fallen over the Forest of Dean. In the clearing where we left the microphones, the cool nocturnal air has begun to echo with the calls of tawny owls. Cars passing on the distant forest road hush like banks of wind through the high tree tops. Down on the forest floor, hidden beneath the twisted vines, a stream is revealed. Its watery eddies sparkle brightly through the darkness, reflected and amplified by the broad leaves above. When there's no light in a forest everything sounds different. Sharper. What was close, is closer. Reverberant. What was far, is farther away. But between the echoes, there is silence. Between the tree trunks, branches crack, a creature squeals, a distant dog barks. Murmurs of murmurs seep through from the outside world. Falling softly on the gnarly bark of this ancient tree, in this giant forest where the owls live, these are the sounds of the night-time passing.