"O is for Obedience" is the fifteenth episode of the second season and the forty-first episode overall of W.I.T.C.H. It first aired September 23, 2006.
In the B-story, Irma and Martin Tubbs start flirting, and Irma overcomes her control issues.
- It is revealed that Nerissa is Caleb's mother.
- Caleb's age is questioned, as in the first episode of season 1, Caleb says he is fifteen years old, but in this episode it is stated that Caleb was born seventeen years ago. This question is highlighted by the fact that season 1 only unfolds over months, at the most, and season 2 continues immediately after season 1, making it impossible for 2 years to have passed.