Succubus Elaine, resembling the deceased Caleb, becomes assistant to CEO Sebastian. Trapped in guilt over his late friend Colin, Sebastian treats her as a substitute. Each is a shadow of the other's lost one, yet they fall in love through their contract. Facing his brother Jasper's schemes and identity struggles, they must break free from the substitute bond, distinguish guilt from true love, overcome rumors and crises, achieve self-reconciliation, and find a love truly their own.