A true historical drama about King Sejong, the greatest ruler in Joseon history who sought to enhance national prosperity and military power through astronomy, and Jang Yeong-sil, the most remarkable scientist.

Cave paintings and lunar calendars exist in the caves and remains of prehistoric hunters studied recently. What if Prehistoric Man were clever enough to develop in depth scientific knowledge? As unlikely as it may seem, new data tend to prove that Prehistoric Man actually invented Astronomy!