When we started out on our hike to the top of Sunset Peak on Hong Kong’s Lantau Island this morning, the sun was only feebly leaking through a grey and milky sky and the contours of the land were indistinct in the distance. Despite a steep initial climb, the lack of full sun and the resulting cool temperatures dictated that long trousers and fleece tops were the clothing order of the day; but, barely a few minutes before this photo was taken, we passed through an almost imaginary line in the sky and the atmosphere totally changed. Suddenly we were stripping off layers of clothing, the air actually tasted sweeter, we could see for miles and the sky became a beautiful deep blue – we had escaped the layer of haze and pollution that can envelope Hong Kong at this time of year; trapped and contained beneath a meteorological ‘inversion layer’. In the background of the photo is Lantau Peak, clearly showing this not-so-imaginary line in the sky. Unfortunately ‘what goes up, must come down’ and, after a wonderful couple of hours spent hiking in this territory we had to descend steeply back down into the muck – hard on our lungs, our thighs and our spirits!