The men on the spaceship Quetzal had a mission to perform, but everything indicated it would be a simple matter to set up a refueling station on the planet Gwydion. Advance explorations had already determined that the inhabitants of Gwydion were few in number and thouroughly amiable in their ways. In fact, such concepts as anger, thievery, murder and warfare did not exist for them. All that remained for the Quetzal was to find a suitable site and cement friendly relations.
But with the change of season and the bursting of the countryside into blossom, strange things began to happen. There was talk of a mysterious cycle and a day of danger. What was the secret the Gwydionites themselves dared not mention? How would it affect their spacemen visitors?