Ever since the widespread experience of heat amongst the girls of CHS, Sunset has been wracked with guilt over one particular consequence, that which happened to Derpy. To try and make up for it, she's tried everything she can to support the girl during this difficult time.

However, during some time with her, Derpy reveals something important to the former unicorn. Something which shocks the her immensely.

Part of the Rainbooms/Dazzlings/Shadowbolts storyline.