Spark

Ga-ohn, leader of the up-and-coming K-pop idol group Dexter, visits his late grandmother's memorial to share news about his long-awaited debut.

Found unconscious, Ga-ohn gets transported to the hospital; the doctor doesn't find anything particularly wrong with his health.

To figure out the mystery behind his physical ailment, Ga-ohn takes Ha-neul back to the set of his music video to re-enact the night's events.

Ga-ohn gets angry at Jae-kyung for accusing Ha-neul of stalking him; Ji-seung tries to console Jae-kyung as she goes on an eating binge.

Surprised that Ha-neul's ringtone is his favorite song, Ga-ohn asks her how she knows it and discovers that the two share an unexpected musical bond.

While Ga-ohn is working on a new song, Ha-neul accidentally falls asleep and loses her grasp on Ga-ohn; to their surprise, Ga-ohn isn't hurt.