In Chapter 1 of The Chrysalids, what special deviation did David talk to Mrs. Wender about?
In Chapter 1, David confesses to having seen the deviation of Sophie's six toes. David had gone to his favorite sand dune to slide down the slope when Sophie happened along. She inquired whether his game is fun. The two slide down having fun together until Sophie's foot get trapped. In order to free her foot, David tries to encourage Sophie to remove her shoe, a suggestion she loudly resists. She eventually gives in though because her foot is really hurt, and they can't get it free.
David is surprised by seeing six toes on Sophie's foot but gives it no further thought. David takes her home to her mother Mrs. Wender, who asks David all manner of solemn questions. Finally, David confesses that he saw the extra toe on Sophie's foot. Mrs Wender talks with David, explaining the importance of his discovery and the seriousness of Sophie's secret. Mrs. Wender pleads with David to keep the secret that he discovered and to tell no one.
David promises wholeheartedly and quite sincerely. On his way back home the words of the Definition of Man, taught to him in school, come to his mind and echo there: "And each leg shall have...one foot and each foot 5 toes." Suddenly the true horror of Sophie's problem dawns on him.