As is typical across many genres of European folklore, the titular beings in The Watchers turn out to be changelings. When faeries abduct a human, usually a youngster, they often turn to changelings, magical beings who take their place. Legends about changelings vary differently from one culture to another, but generally speaking, a child's inability to develop normally, odd behaviour, or even exceptional intelligence are telltale signs that they are a changeling. Ancient peoples used the story of changelings to make sense of mysterious diseases and developmental problems like autism spectrum disorder, which modern science has confirmed.
