One day, in the salt marshes of the eastern Algarve, a small bird with an orange chest and feathers the color of the sea, the kingfisher, spots floating litter. Curious yet uneasy, he decides to investigate the origin of those strange residues.
Following their trail, the kingfisher arrives at a picnic area and discovers that all that rubbish has accumulated along the watercourses, giving rise to a huge monster. Anxious, he decides to ask his friends for help to put an end to the pollution that has plagued the salt marsh, but they end up discovering something even more frightening…