Teen Titans (TV Series) Episode: Nevermore

During a battle with Dr. Light, Raven (Earth-Teen Titans) loses control of her powers, which makes the Titans worried. Later Beast Boy and Cyborg sneak into Raven’s room and Beast Boy discovers a strange-looking mirror, which sucks him and Cyborg into Raven's own mind, which they originally believe to be her home dimension, Azarath. When Raven finds them there, she tells them to leave, because her father (he remains unnamed until the 4th season but is, in fact, the demon Trigon (New Earth)) is wreaking havoc in her mind. Beast Boy and Cyborg stay and aid her, eventually proving that they truly do like her and are her friends.