Dave Roach, fresh from his two years of National Service in 1955, visits relatives in the Suffolk village of Butley, which is on the eastern edge of Rendlesham Forest. Two children have disappeared in open view of their friends and stories emerge of strange craft in the sky and strange visitors in the forest. His curiosity draws him into making a few enquiries and he becomes involved in an act of invasion both subtle and far-reaching. The story is told by his friend and is taken largely from the diary Roach kept at the time.