A Wind in the Door is a young adult science fantasy novel by Madeleine L'Engle. It is a companion book to A Wrinkle in Time and part of the Time Quintet. Plot summary 14-year-old Meg Murry is worried about her brother Charles Wallace, a 6-year-old genius bullied at school by the other children. The new principal of the elementary school is the former high school principal, Mr. Jenkins, who often disciplined Meg, and Meg is sure has a grudge against her whole family. Meg tries to enlist Jenkins's help in protecting her brother but is unsuccessful. Later, Meg discovers that Charles Wallace has a progressive disease that is leaving him short of breath. Their mother, a microbiologist, suspects it may be a disorder of his mitochondria and his mitochondria's farandolae. (The farandolae are micro-organelles inside mitochondria that exist in the Time Quintet fantasy universe.) One afternoon, Charles Wallace tells Meg of a "drive of dragons" in their backyard, where he and Meg thereupon discover a pile of unusual feathers. Later, Meg has a frightening encounter with a monstrous facsimile of Mr. Jenkins. That night, Meg, Charles Wallace, and their friend, 16-year-old Calvin O'Keefe discover that Charles Wallace's "drive of dragons" is an extraterrestrial "cherubim" named Proginoskes (nicknamed 'Progo' by Meg), under the tutelage of the immense humanoid Blajeny, who recruits the three children to counteract the Echthroi. Meg's first task, on the next day, is to distinguish the real Mr. Jenkins from two Echthroi doubles, by identification of the (potential) goodness in him despite her personal grudge. The protagonists then learn that Echthroi are destroying Charles Wallace's farandolae, and travel inside one of his mitochondria, to persuade a larval farandola, named Sporos, to accept its role as a mature fara, against the urgings of an Echthros. In the process, Meg is nearly annihilated, and Mr. Jenkins is invaded by his Echthros doubles; whereafter Proginoskes sacrifices himself to "fill in" the emptiness of the Echthroi, and Charles Wallace is saved. Characters Meg Murry is a high school student, a defensive misfit who gets along best with her family and her friend Calvin O'Keefe. She wears glasses, has brown hair, and initially considers herself "repulsive-looking" and "dumb", although she is quite good at math. By the time of A Wind in the Door, Meg is much happier in school than previously, in part because of her friendship with Calvin, but is deeply