What was darrys biggest fear

Darry's biggest fear was losing Ponyboy (or Soda) as they had lost their parents. This is revealed in Chapter 6 when Darry and Sodapop visit Ponyboy in hospital. Ponyboy finally realises that the reason that Darry has been so hard on him is because of his love for his brothers, not because he does not like Ponyboy. This has been a crucial lesson for the boys, and gives Ponyboy some of the strength needed to face the dificult events ahead.