When a substitute becomes the only way to survive, performance means survival.
Crossing the boundary between the slums and the wealthy, she was forced to play the role of the dead perfect sister and become a bargaining chip for business marriage.
However, every detail of the imitation is approaching the truth: my sister's death was not an accident.
The most dangerous thing is that the cold fiancé has already seen through everything, but chooses to become her accomplice.
Between sophisticated lies and fatal truths, false identities temper the toughest souls - from chess pieces at the mercy of others to people who hold chess to overturn the chess game.
When the monitor and the performer become accomplices, in this substitute game, the true self will be won in the end.