The King’s Letters

King Sejong the Great of Korea seeks to create a simplified writing system to promote literacy among the general population, moving away from the Chinese characters traditionally used. He enlists the help of Buddhist monks, including Shinmi, due to their knowledge of phonetic languages like Sanskrit. Sejong promises to build a Buddhist temple if they succeed.

To maintain secrecy, the monks are disguised as court eunuchs and work secretly within the palace. Queen Soheon, secretly a Buddhist, welcomes the monks, supporting their clandestine project amidst tensions between Buddhists and Confucians at the court.

King Sejong's health deteriorates due to diabetes, causing him to lose sight in his right eye and prompting him to seek medical treatment. His doctors advise him to avoid stress, leading him to retreat to a mountain spa where he can rest and recover.

While in the remote location, the monks successfully complete the new writing system, which would become known as Hangul or Chosŏn'gŭl. The project concludes with the monks having achieved their goal of creating a phonetic alphabet.

Sejong returns to the palace and faces a power struggle between Buddhists and Confucians. Both factions seek credit for the invention of Hangul, with the Buddhists expecting acknowledgment per their agreement, while Confucians aim to maintain political dominance.

Under pressure from political factions, Sejong decides to appease the Confucians and dismiss the Buddhist monks, sending them away despite their vital role in the project. This decision causes tension among the monks and the royal court.

Queen Soheon, secretly a Buddhist and deeply affected by the monks' departure, sacrifices herself by starving to death to reunite Sejong with Shinmi. Her death leaves Sejong grief-stricken and more determined to honor her wishes.

Grief-stricken, Sejong recalls Shinmi to the palace, leading to a reconciliation. Sejong fulfills his promise by constructing a Buddhist temple, and Shinmi presides over Queen Soheon's funeral, symbolizing unity and respect for Buddhist traditions.

Sejong reflects on his thirty-year reign and his desire to leave a lasting legacy through a single book that embodies his efforts. Shinmi uses an allegory to suggest that this book will have an immeasurable impact on Korean society.