When a creature makes a ranged or melee attack against a cerynitis, targets her with an ability, or includes her in the area of effect of an ability, the cerynitis can move up to half her speed as if she had readied an action to move. If she moves at all, this foils ranged and melee attacks; if she moves out of the area of effect, she avoids an area of effect ability; if she moves out of range of the targeted effect, she avoids a targeted ability. Once she uses this ability, a cerynitis can't use it again for 1 round. Each use of this ability counts as a move action for the purpose of triggering Lightning Stance. A cerynitis can't use unearthly speed to avoid an attack or ability if she is not aware of the attack or ability, and she cannot use this ability at all if she is rendered immobile or if she bears a rider.