Aideen, the esteemed daughter of a duke, is the Emperor’s assassin and the leader of ‘Owl.’ For giving everything and serving her Lord faithfully, she was betrayed and sentenced to death by guillotine. Abandoned by her Lord, her life came to an end, yet the moment she opened her eyes again, she realized she had returned to a time when she was still only 17. In order to get her revenge, she decided to destroy Ferdi, a country that the Emperor cherished more than his life. *"You are beautiful, Milady. Especially those red eyes of yours."* The man who personally sent the order to have Aideen executed, the Prince from the enemy country, Diceon, unexpectedly began to interfere with her life! The story of Aideen, the woman who was abandoned by the Emperor and was given a second chance at life to get her revenge and to destroy her home country, now unfolds!

The explosion at the Geonyang chemical plant 19 years ago was not an industrial disaster. There was a secret experiment to awaken 'it' that had been sleeping underground in the city, and dangerous particles that had been dormant for hundreds of millions of years spread throughout the city through factory chimneys. A city that died in a disaster, but people still lived and children were born. The 'things' that were released to the ground in the past also coexist in the darkness of the city. The summer of 1999, when the children born the year after the accident turned 18! Once again, the secret in the darkness is about to awaken... In 1999, various mysterious events occur in a village at the turn of the century. Fearless girls and children who investigate the case, and various unidentified monsters. On the contrary, the adults who try to cover up the incident and 'it', the source of everything, are revealed! (Source: KakaoPage, translated) *Note: Chapter count includes a prologue.*