Synopsis: Ethel and Tommy Barrick don't particularly enjoy boarding school and normally look forward to their holidays with excitement. This summer however, they face the long break with a real feeling of unease.
Their father is to remarry and sends the children to Ireland to spend the summer with his bride-to-be, a woman they have never met. Once in Ireland, the children quickly grow to dislike their father's fiancee. Their worst nightmare is realized when they discover she is actually an evil water banshee with real magical powers and a hatred for all things green!