Sinopsis

Recovering from coughs and colds, the children are prescribed a holiday in the Welsh mountains. Days of tobogganing, skating and snowmen lie ahead, but the children soon become distracted by a mysterious local building called Old Towers. Having seen ‘shimmerings’, and vans visiting the place in the dead of the night: surely there is something strange going on? When the Five go to stay in a Chalet near Old Towers they discover some breath-taking secrets involving the atmospheric building.