Yeonjun is the first one to feel something’s wrong.

At first, it’s small things: mirrors fogging up without steam, his reflection moving just a second too late, saltwater in his shoes even though he hasn’t been to the beach. He brushes it off, until he sees her—the same crying girl from Taehyun’s dreams—standing at the edge of the cliff while he's out on a late-night walk. But when he runs to help her, she vanishes into thin air, leaving only the faint echo of a piano melody on the wind.

From that moment on, Yeonjun starts changing. He becomes more withdrawn, distracted, even aggressive at times. The others notice. What they don’t realize is that he’s slowly being possessed by the spirit of the lost musician—the one who disappeared all those years ago.

Turns out, Yeonjun shares a soul-tie with him. The musician is using Yeonjun to finish the final song he wrote for his lost love... the same girl haunting the cliffs.

But if Yeonjun completes the song under the full moon, the musician will fully take over his body, and Yeonjun will disappear forever.

The members must figure out how to break the curse—before the final note plays.