One day, Mo Chuan, an exorcist, accidentally unseals an ancient demon who has been trapped for hundreds of years and accidentally forms a contract in the process. Now Mo Chuan wants nothing more than to reseal this demon. The demon wants nothing more than to get rid of Mo Chuan to regain his freedom. This begins a fierce battle of wills. However, in the process of contentiously working together, something in their feelings towards each other seems to be slowly and subtly changing...