An evil vampire has ruled over the kings of an imperial dynasty for centuries.

Only those who are willing to obey Vampire Gwi (Lee Soo Hyuk) have ever been allowed to rise to the throne. When Crown Prince Jung Hyun (Lee Hyun Woo) refuses to bow to the vampire to inherit the throne, Gwi kills him, but not before the prince writes a secret plan to overthrow the vampire under the pseudonym “Lustful Student.”

The prince’s friend, a handsome scholar named Kim Sung Yeol (Lee Joon Gi), accidentally acquires vampire powers and becomes the only person who can defeat Gwi. With Gwi in constant pursuit, Sung Yeol manages to remain in hiding while he searches the land for the long-lost secret plan to defeat Gwi.

About 120 years later during the Joseon Dynasty, Sung Yeol solicits the help of Jo Yang Sun (Lee Yoo Bi), a female bookseller who passes herself off as a man in order to support her struggling family, to locate the secret document authored by the late Crown Prince Jung Hyun.

Meanwhile, Crown Prince Lee Yoon (Shim Changmin) also is snooping around trying to find a childhood friend that he entrusted with a valuable box. Can Sung Yeol find the secret plan and stop the sinister Gwi before he becomes too powerful?

“Scholar Who Walks the Night” is a 2015 South Korean drama series directed by Lee Sung Joon. It is based on a webcomic written by Jo Joo Hee and Han Seung Hee.