In the year 1969, a group of outdoor picnickers in the English countryside came under attack from an unknown enemy. One of the picnickers was Leila Carlin, the sister of Peter Carlin, who was a military combat aviator of some skill; another was Peter himself. During the attack, Peter took the time to shoot photographs of whatever had attacked them, but was forced to flee without having a chance to get the photographs developed. Peter Carlin was the only surviving picnicker. The other two both died.