Having gone for an evening walk near where I lived on the edge of Salisbury plain along the edge of the imber trail I suddenly heard a woosh of birds in formation flying past. Not being visible they etched out in my mind this carving out of the sky, leaving white trails behind them. The images of the birds I wanted to create were the fastest birds around, the swift. My love of the moon depicting an otherwise still night was set under the nearer trails, leaving a rather blank space in the top left of the pic so recreated the same trails again but trying to keep the detail there.