Gezz, Luke and Malcolm are enjoying a trip up Winter Hill on the West Pennine moors when they are joined by a fourth person, a boy wearing old-fashioned clothes and a grey flat cap. But, when Luke introduces himself, the boy fades into nothing! Is he a ghost? Soon, the wilderness is full of apparitions, and all the clues point to the television transmitter at the hill's summit. Where are the spectres coming from? Why are they appearing? And what are their intentions? As the ghosts start to haunt the children's housing estate, Gezz, Luke and Malcolm take their robot friend Anne Droyd up Winter Hill, hoping her superhuman powers will help them solve the mystery. For one of them, life will never be quite the same again.