Episode 4: Secrets of the Palace
Prince Lee An and Su Hee-joo forge a secret pact, and the truth behind the royal archives begins to surface
Episode 4: Secrets of the Palace
Air Date: July 13, 2025 | Rating: 8.3% (Series High)
Synopsis
Prince Lee An confides in Su Hee-joo: he believes a palace fire three years ago was no accident — someone deliberately destroyed a classified archive. That archive, he suspects, holds the key to his mother's death.
As a historian of the Joseon court, Su Hee-joo knows exactly how this story ends. She knows who was behind the fire. But how can she help Prince Lee An without altering the course of history itself?
Key Scenes
The Secret Pact in the Study
Deep in the night, Lee An brings Su Hee-joo to his private study. They sit across from each other in the lamplight, the silence taut.
Lee An: "I am now certain you are from a place I do not know. But if you truly hold the truth about that fire — you must tell me."
Su Hee-joo: "…If I tell you — will history change?"
Lee An: "History is written by people. People can change it."
This exchange sits at the heart of Episode 4. It is the turning point in their relationship — the moment two people from opposite sides of time acknowledge each other's reality.
Discovery in the Secret Archive
The two venture deep into a hidden palace repository. There, among crumbling documents, they find a damaged record. Su Hee-joo looks at the handwriting on the page — and freezes.
It is the same handwriting she saw on a historical source document back in the modern-day library.
Which means: what she is about to experience, and what actually happened in history, have already begun to intertwine.
Why 8.3% — A Series High
Ratings Breakdown: The 8.3% national rating is the highest the show has achieved to date. Three factors drove the surge:
- The chemistry breakthrough — The study scene's eye contact became the most clipped moment in Korean drama social media that week
- Narrative convergence — The mystery arc (palace fire) and the romance arc fused in a single episode for the first time
- IU's performance — Su Hee-joo's breakdown upon recognising the handwriting was widely called the finest acting moment in the series so far
Su Hee-joo's Dilemma
The episode forces the show's central ethical question into the open: Su Hee-joo is a trained historian who believes deeply in non-intervention. But Lee An's grief is real, his loss is real — and she alone holds the answers he is searching for.
Thematic Note: The tension between knowing the future and choosing not to act echoes classical time-travel ethical debates, but the show grounds it in something more intimate: the cost of watching someone suffer when you could help. The drama asks — is the integrity of history worth more than one person's pain?
Next Episode
Episode 5: A mysterious woman appears in the palace, claiming to know "Su Hee-joo." Could there be another time-traveller?