A series about a girl named Lilith who discovers a ruby in a dark alleyway. She is not sure where it comes from or who it belongs to, but she decides to keep it, but then the next day she has a mark on her wrist, and she is keeping it a secret from both her friends and her little brother, and she was starting to feel more strange... What could go wrong if you keep a secret from them? (GACHA WEBTOON)