WHEN I TURNED AROUND

Taking a narrow pathway from the station, late one evening, I suddenly felt a blast of icy-cold air on my back and heard a snigger. Turning to confront the joker, I could see no one, no person, that is, but a silvery spiral of mist curling up from the ground. It swayed menacingly towards me. Terrified, I turned and ran. The coldness at my back remained and i knew it was still close behind me; could hear it sniggering.
Gasping for air, my legs like lead, I reached the main road at last and in my panic, dashed straight across. Then, frozen with fear, I saw the speeding motor-cycle heading straight for me but at the last minute the rider swerved.
Behind me, something screamed. The cyclist, unaware, was well away in the distance but the silver misty column was writhing on the ground, gradually disappearing into the tarmac.