Blue Cocoon follows the story of Cynthia, a woman who lives alone, isolated from the outside world. Her day-to-day routine involves listening to an old grammar phone and the catching and killing of butterflies in vicious traps that hang from her window. One day, this routine is disrupted as a curious young girl enters her garden unexpectedly. Cynthia is besotted by the girls’ grace, youth and beauty and in her deranged, intoxicated state, decides to kidnap her using the chloroform that she uses on her butterflies, and on herself recreationally.