Lee Chung is a Prince of Joseon, but he has been taken hostage to the Qing Dynasty. He enjoys boozing, womanizing and gambling. He is also an excellent swordsman. His older brother Lee Young will succeed to the throne and brings Lee Chung to Joseon. He returns after more than 10 years. Soon, Lee Chung faces monsters that run rampant in the night.

Hoon-Nam knows about love theoretically, but he rejects falling in love. Jung-Eum wants to fall in love, but, due to her difficult situation, she gives up on finding love. Hoon-Nam and Jung-Eum meet and develop a relationship romantically.

Sim Deok-soo is a grumpy landlord running a run-down apartment complex. Suddenly his tenants begin disappearing under suspicious circumstances. A retired ex-detective shows up, claiming a serial murderer from 30 years back has returned.

Seo-Ri's mother Queen Sim was unable to have a child. She went to a shaman to help her have a child. With the help of shaman Hong-Joo's black magic, Queen Sim was able to have a boy and girl twins. The girl, Seo-Ri, was put under a curse and abandoned deep in the mountains. She meets Heo Jun, a young man, there.

The fictional story begins after the execution of real-life North Korean general Jang Sung-taek. One day an order comes down from North Korea, reactivating erstwhile spy Park Hye-rim who has spent decades in South Korea as an ordinary housewife. She is given the mission to turn and bring in her own son, Kim Seonu. Cool-headed, quick-witted genius Seonu is an information analyst on North Korea working for the NIS. His girlfriend Yoon-jin is a tour guide for Chinese tourists who cannot speak Chinese, and they fell in love when Seonu helped her translate. Hye-rim is suddenly forced to choose between her son and country, and risks her life to see the choice through.

Ji-hyuk is an expert safe-cracker who lives the highlife stealing antiques and jewelry with his team. CHO, a powerful and cruel gang boss threatens them to steal $150 million with him. Ji-hyuk plans to get revenge on CHO, but ends up falling into his trap. However, CHO later realizes it was all part of Ji-hyuk’s scheme. When Ji-hyuk, who was thought dead, reappears, hidden secret relations between the technicians also surface.

On the eve of the founding of the Joseon Dynasty, a whale swallows the Emperor's Seal of State being brought to Joseon by envoys from China. With a big reward on whoever brings back the royal seal, mountain bandits led by Jang Sa-jung go out to sea to hunt down the whale. But he soon clashes with Yeo-wol, a female captain of pirates, and unexpected adventure unfolds.