Beomgyu’s the last one to believe in any of it.

He thinks Yeonjun’s just being dramatic, Taehyun’s dreams are just dreams, and the whole “haunted musician spirit” thing? Please. But that all changes when he starts hearing the music.

At night, while the others sleep, Beomgyu hears a faint melody—like a lullaby—coming from the attic. Every time he goes up, the piano is still, untouched, dusty. But one night, the melody changes. It starts calling his name.

That’s when he finds a diary hidden under the floorboards, written by the girl who vanished. She writes about her love for the musician, but also about someone who betrayed them—a friend who played it off as a joke, someone who laughed at the warnings until it was too late.

Beomgyu realizes he’s reliving the role of that friend.

Now, stuck between wanting to protect Yeonjun and not wanting to admit he’s scared out of his mind, Beomgyu becomes the wild card. He pretends not to care, cracks jokes, acts reckless—but secretly, he’s the one researching, making protection charms, and keeping watch over Yeonjun every night when no one else knows.

And when the climax hits, it’s Beomgyu who puts himself in danger to break the bond between Yeonjun and the ghost—even if it means offering his own soul in Yeonjun’s place.

Because that’s what best friends do, right?