In the Nine Puzzles episode 5, it takes a turn that no one saw coming. The story keeps building with more layers, more doubt, and a lot of confusion. Viewers get to see I-na trying to figure out why she received the third puzzle piece, especially when she’s convinced Yang-hee was the one who killed Chi-muk. She’s panicked. It doesn’t make sense to her at all. If Yang-hee killed Chi-muk, then why did she get the puzzle? That’s where things get strange.
At her office, I-na shows the puzzle piece to the others. The red lines on the piece match exactly with how Chi-muk’s body was cut. The shocking part? That kind of detail was never shared in the news. It’s something only the killer would know. This makes I-na think maybe Yang-hee wasn’t the killer after all. Maybe someone else is trying to send a message—maybe the real puzzle killer.
I-na decides to visit Yang-hee in prison. She shows her the puzzle piece. Yang-hee looks surprised. The lines on it match the exact cuts she made. I-na then asks if Yang-hee ever felt like someone was watching them. Yang-hee remembers something. Yes, near the hotel, she did feel watched. That adds to I-na’s suspicions.
They talk about the suitcase found near the water. I-na says they followed the dragging trail to find it. But Yang-hee corrects her. They didn’t drag the suitcase. They carried it. That detail doesn’t match. Something’s clearly off.
A New Case: Young-han’s Poisoning
Then, a new case pops up. An older worker, Young-han, dies from poisoning. He had been drinking with three friends. I-na starts to look at this new case closely. It feels too clean, too planned. The way the victim died, the timing, and the setting—it all fits the puzzle killer’s style. Cold. Detailed. Very calculated. Minimal clues.
Young-han’s death causes a stir. The officers start asking questions. Each friend gives a full story about what happened the night before. But they’re not easy to believe. One of them, Jung-chul, owed Young-han money. Another, Deok-mun, took 35 minutes to come back with snacks when the shop was just five minutes away. He didn’t even drink that night.
They also find out that Young-han died from nicotine poisoning. That’s when things get more interesting. Gajbe, who was there that night, smokes cigarettes. His brother-in-law runs a vape shop. All three are under suspicion now.
I-na and Han-sam try to figure it out by pretending to be the three friends. They want to understand how each of them thinks. Slowly, they start to rule them out. None of them fit the killer’s pattern. They don’t seem capable of such planning.
Puzzle Killer or Personal Revenge? A Deeper Look
I-na tells Han-sam that the killer’s personality feels familiar. It matches the puzzle killer. That’s when Han-sam remembers the janitor. He’s always around. He goes to the container every day and dislikes the three men. He says it’s just part of his job, but the timing seems strange. Something doesn’t add up.
The janitor then shares a key detail. A year ago, something terrible happened. Young-hoon’s son died while working at the factory. Jung-chul had shown his son what to do and then left him alone while he drank with the others. The boy’s hand got caught in a machine. He didn’t survive.
Suddenly, the focus shifts. Maybe this isn’t about the puzzle killer. Maybe this was about revenge. In a flashback, we see Young-hoon himself placing the poisoned drink. He drank it too. It wasn’t about getting away. It was about making a point.
But I-na is still thinking. If Young-hoon wanted to kill them, why didn’t he have a better plan? And why didn’t he just frame them more clearly? That’s where things take another strange turn.
I-na visits Han-sam again. She brings the third puzzle piece. She has a theory now. What if the people they thought were victims—like her uncle Doog-hoon, Miyoung, and Chi-muk—weren’t innocent? What if they were hiding something & if they were involved in something terrible?
She tells Han-sam that she’s starting to think there are more people involved. Maybe more than anyone imagined. She believes there are still hidden truths. More culprits. And the puzzle isn’t done yet.
Kavita Mishra is a dynamic writer and passionate Korean entertainment enthusiast, combining her love for K-pop and K-drama with a flair for storytelling. With a keen eye for the latest trends, Kavita crafts articles that capture the pulse of K-pop idols, chart-topping hits, and the most buzz-worthy dramas taking over screens worldwide.
