Actors : Song Seung-heon, Park Ji-hyun, Cho Yeo-jeong, Directors : Kim Dae-woo,
Seong-jin, a conductor, and Su-yeon, a cellist, are engaged. Su-yeon disappears, leaving a video. Mi-joo replaces Su-yeon and develops a secret relationship with Seong-jin. They feel watched as their bond deepens.