

Yolanda's operational error during surgery left a patient paralyzed and triggered a heart attack in herself out of shock.Desperate,Yolanda's mother pleaded with Carolyn to take the blame and serve the prison sentence in Yolanda's place. Deeply in love with Yolanda's brother, Frazier, Carolyn agreed to the request but kept everything secret, intending to explain the truth to him after her release. However, while in prison, Carolyn was diagnosed with cancer. Thus, she chose to conceal the truth indefinitely rather than cause Frazier further pain. Then, she secretly dedicated her final days to supporting him—helping his company develop an anti-cancer drug, and even donating her heart to his sister after her death. But Frazier knew nothing about it and still had a misunderstanding of her even after her death. At last, overcome with regret, he chose to die.

In the fog-choked steam city of Verlock, Chloe Ashborne survives a brutal family massacre and hides herself as a disfigured, mute maid sneaking into the obsidian Clock Tower Manor—the stronghold of the cold and powerful Duke Liam. Covered in wax scars and pretending to be timid and clumsy, she hides her true identity as the last heir of the Ashborne mechanical clan, a master toxic healer, top gear decoder, and deadly combat fighter. Her only goal is to retrieve the sealed case files that record the truth of her family's murder from the manor's confidential machine room. As she lurks in the shadows, she repeatedly arouses Liam's suspicion and curiosity. She narrowly escapes frame-up and fatal traps set by the jealous captain of the female guards, saves Liam from fatal steam poison and assassin attacks, and secretly controls the manor's defense gear system in crisis. While the line between hatred and attraction blurs, Chloe's layered disguises are gradually stripped away one by one. When she finally breaks into the secret chamber to obtain the files, she falls into a carefully laid trap, and her true face and identity are completely exposed to Liam. The two fall into misunderstanding and confrontation, until the real murderer behind the massacre launches a full-scale attack on Clock Tower. Standing amid fire, gunsmoke and collapsing steam machinery, Chloe and Liam lay down their hatred, fight side by side to defeat the evil guild, uncover the buried truth, and turn a revenge disguise into a fated love bonded by gears, steam and redemption.