Inho Kang is a respected employee within Dahlia’s Court company, who suddenly loses his life in an unexpected incident. When he wakes up, he finds himself in another body. He is now Suhwan Choi, a recently hired employee with a dangerous secret. A diary left behind by the late Suhwan turns Inho's world upside down when he realizes the people he trusts may be involved in his death. This is a joint cooperation between a man who won't die and a man who, even in death, still seeks for revenge.