The father of Ellen (Karen Sillas) and her sister, May, died some time ago, and May has started living in the family's broken-down, bug-infested cabin. While visiting May, Ellen discovers that May has a handsome new lover named Peter and that May is pregnant. May is due to give birth soon, but is having severe abdominal pains. Peter seduces Ellen, who has always been competitive with May (but has long denied it). Both the truth about Peter and his reason for seducing Ellen soon become clear.