A group of unlikely heroes from across the Korean peninsula try to save the day after a volcano erupts on the mythical and majestic Baekdu Mountain.

Ju-young is a young woman with a hearing impediment who decides to investigate her sister's inexplicable disappearance, last seen in her apartment. Feeling more and more cornered, Ju-young begins to hear strange sounds and sense an evil presence in the apartment.

Korea, 1645 - Joseon Dynasty: a partially blind and gifted acupuncturist, Gyeong-su, is invited to work alongside the royal physician in the palace of King Injo, just before the crown prince Sohyeon returns after having been held captive by the Qing Dynasty. Prince Sohyeon and his father begin to differ in opinion on the future direction of their dynasty, leading King Injo to suffer from severe anxiety and paranoia. One night, Gyeong-su witnesses prince Sohyeon's death. Disbelieved as a witness on account of his blindness, Gyeong-su must struggle to reveal the truth while not falling prey to the power-hungry conspirators of the palace.

Born between a Sorrikkun (a traditional musician) father and a Gokbi (a dirge singer) mother, Dong-hyuk follows their legacy and lives out his life teaching Gukak (Korean traditional music) at a university. Then one day, as Dong-hyuk's wife Yeonhee becomes stricken with Alzheimer's disease, Dong-hyuk 's successful life gets hard.

Once known as the frontman of the rock band Ambulance during his college days, Seung-min now lives a quiet life running a small instrument shop. One day, his legendary first love Bo-na, the girl he never even had the courage to confess to before she suddenly disappeared, unexpectedly reappears in his life. From that moment on, Seung-min's heart begins to race again. But as old feelings resurface, he finds himself trapped in an awkward predicament: a secret he must never let his first love discover… no matter what.

Two guys who are working for cartels as cleaners get a request to monitor an 11-year-old kidnapped girl, but the situation gets worse when their supervisor gets killed.