Two young children who live in a small town called Stattfield (fictitious), have befriended two strange creatures that live in the large, deep pond at the bottom of their garden. Their neighbour is a young child and friend of about the same age who shares this relationship with the 'pond people'. One evening, just before suppertime, a most unusual event occurs which changes the lives of the children and their immediate families literally overnight. They become heavily involved in a race against time to protect and rescue a group of extraterrestrials from an ignorant public. The children come up with a diabolical plot to save the aliens right under the noses of the very government officials who would have instigated their annihilation.