I Saw the Devil (2011) Timeline Explained – Every Event in Order

Soo-hyun forces Kyung-chul to swallow a GPS tracker after capturing him because he wants to monitor the killer's movements and overhear his conversations. This allows Soo-hyun to track Kyung-chul's location in real-time and gather intelligence about his actions and plans. The tracker becomes crucial in Soo-hyun's cat-and-mouse pursuit, letting him stay one step ahead while Kyung-chul continues his violent rampage across the city.

Foreshadowing: Earlier, Soo-hyun discovered Joo-yun's ring at Kyung-chul's home, confirming his identity as the killer and driving his obsession with tracking him.

• tracker device
• Soo-hyun
• KYUNG-CHUL
• GPS tracking
• revenge method

Kyung-chul discovers Soo-hyun's identity when he visits his friend Tae-joo, another serial killer and cannibal. During this meeting, Soo-hyun's presence and the context of their conversation reveal to Kyung-chul who has been tormenting him. Once Kyung-chul realizes Soo-hyun is the one pursuing revenge for Joo-yun's murder, he becomes equally fixated on getting revenge against Soo-hyun, turning the cat-and-mouse game into a two-way pursuit.

Foreshadowing: Soo-hyun had already been monitoring Kyung-chul through the tracker, positioning himself closer to the killer's inner circle.

• KYUNG-CHUL
• Tae-joo
• Soo-hyun identity
• discovery
• revenge pursuit

Kyung-chul targets Squad Chief Jang and his daughter Se-yun as part of his twisted revenge against Soo-hyun. After learning that Soo-hyun is Joo-yun's fiancé and the one hunting him, Kyung-chul plans to hurt Soo-hyun by attacking the people connected to the investigation. Since Squad Chief Jang is Joo-yun's father and the police officer leading the search for the killer, Kyung-chul sees harming him and Se-yun as a way to inflict maximum pain on Soo-hyun. Tae-joo inadvertently reveals this sinister plan during a hospital confrontation with Soo-hyun.

Foreshadowing: Tae-joo reveals Kyung-chul's plan during a heated hospital confrontation, where Soo-hyun brutalizes him for information.

• KYUNG-CHUL
• Squad Chief Jang
• Se-yun
• attack
• revenge
• family target

The guillotine activates when Kyung-chul's estranged son and elderly parents arrive at the hideout to pay him respects. Soo-hyun had set up the mechanism with a rope that Kyung-chul must hold in his teeth to prevent the blade from dropping. When Kyung-chul's family unexpectedly arrives and approaches him, he is forced to release the rope to embrace them. With no one holding the rope, the blade descends and decapitates Kyung-chul in front of his horrified family. The entire scene was orchestrated by Soo-hyun as his final act of torture and irony.

Foreshadowing: Soo-hyun deliberately arranged for Kyung-chul's family to arrive at that specific moment, having learned about them earlier.

• guillotine
• KYUNG-CHUL family
• death scene
• ironic punishment
• beheading

Soo-hyun cries at the end because he realizes he has become exactly like the monster he hunted. Throughout his quest for revenge, Soo-hyun descended to Kyung-chul's moral level, he tortured, mutilated, and ultimately murdered Kyung-chul in a horrifying way, all while the killer's innocent family witnessed the execution. The tears represent Soo-hyun's recognition that his pursuit of vengeance has destroyed his own humanity. He achieved his revenge but lost himself in the process, leaving him emotionally hollow and morally corrupted.

Foreshadowing: The film establishes early on that Soo-hyun is willing to use extreme methods, first by forcing the tracker into Kyung-chul and later by slicing his Achilles tendon.

• Soo-hyun
• crying
• ending
• moral corruption
• hollow victory

Kyung-chul evades the police initially because he is one of four potential attackers identified during Soo-hyun's interrogation of suspects. While Joo-yun was attacked by multiple people, Kyung-chul's status as a suspect rather than a confirmed perpetrator gives him enough plausible deniability to avoid immediate arrest. Additionally, Kyung-chul is a school-bus driver with a seemingly normal life, which helps him blend in. Soo-hyun must gather his own evidence, including finding Joo-yun's ring at Kyung-chul's home, before he can personally pursue vengeance outside the legal system.

Foreshadowing: Soo-hyun interrogates two suspects early on, learning that Kyung-chul is one of four potential attackers.

• KYUNG-CHUL
• police escape
• suspect
• investigation
• evasion

After Soo-hyun confronts Tae-joo at the hospital, he brutalizes him severely, leaving him a battered shadow of his former self. Tae-joo had inadvertently revealed Kyung-chul's plan to target Squad Chief Jang and his daughter Se-yun during the confrontation. Soo-hyun's violent attack on Tae-joo is driven by rage upon learning this information. The film does not specify whether Tae-joo dies from these injuries, but he is left severely beaten and incapacitated.

Foreshadowing: Tae-joo was already established as a fellow murderer and cannibal, making him a target for Soo-hyun's wrath.

• Tae-joo
• hospital
• Soo-hyun attack
• brutalization
• injuries

Soo-hyun tortures Kyung-chul because simple death would not equal the suffering he experienced from losing Joo-yun and their unborn child. Consumed by grief and rage, Soo-hyun wants Kyung-chul to experience the same terror and pain he endured. His revenge is not about justice or closure, it's about inflicting equal suffering. By creating elaborate torture devices like the guillotine and making Kyung-chul hold a rope to delay his death, Soo-hyun extends the killer's torment as long as possible. This approach ultimately destroys Soo-hyun morally, as he becomes indistinguishable from the monster he hunts.

Foreshadowing: The film opens with Joo-yun's brutal murder, establishing the depth of Soo-hyun's grief and his willingness to descend into moral darkness.

• Soo-hyun
• KYUNG-CHUL
• torture
• revenge
• suffering
• psychological breakdown

Kyung-chul kills the nurse because he needs medical assistance after Soo-hyun slices through his Achilles tendon. Injured and in pain, Kyung-chul approaches the nurse, presumably seeking treatment. However, instead of helping him, the nurse becomes his next victim, consistent with his pattern of targeting vulnerable people. This murder demonstrates Kyung-chul's continued depravity even when injured and desperate, showing that he cannot control his serial killer impulses regardless of his circumstances.

Foreshadowing: Soo-hyun specifically injures Kyung-chul's Achilles tendon as retribution for his crimes, knowing it would cripple him.

• KYUNG-CHUL
• nurse
• killing
• medical treatment
• Achilles tendon injury

Soo-hyun deliberately arranges for Kyung-chul's family to visit because he wants to inflict maximum psychological torture. By forcing Kyung-chul to choose between holding the rope to delay his death and embracing his family, Soo-hyun creates an impossible situation. The arrival of Kyung-chul's estranged son and elderly parents shatters the killer's composure, he panics and releases the rope, triggering the guillotine. Soo-hyun uses the family as a tool to make Kyung-chul experience fear and helplessness in his final moments, turning what should be a peaceful reunion into a deadly trap.

Foreshadowing: Soo-hyun had learned about Kyung-chul's family earlier, using this knowledge as his final weapon.

• KYUNG-CHUL family
• visit
• torture
• Soo-hyun
• psychological warfare
• irony

Soo-hyun finds Kyung-chul even after the killer discovers and removes the tracker device. When Kyung-chul realizes he is being tracked, he cunningly switches the tracker to another driver's vehicle, trying to mislead Soo-hyun. However, Soo-hyun eventually catches on to this deception and continues his pursuit through other means. The film shows Soo-hyun's relentless determination, he does not give up when the tracker fails but instead resorts to more direct methods of hunting Kyung-chul down, eventually capturing him at his hideout.

Foreshadowing: Kyung-chul's ability to discover the tracker demonstrates his cunning, making his eventual capture more dramatic.

• tracker
• KYUNG-CHUL removal
• Soo-hyun
• deception
• pursuit
• hunt

Kyung-chul kills the two taxi passengers as part of his escalating violence and lack of regard for human life. After being released from initial suspicion and given freedom to move around the city, Kyung-chul's behavior becomes increasingly erratic and murderous. The taxi murders represent his willingness to kill innocent people without justification or restraint. These killings further demonstrate his status as a dangerous serial killer whose crimes are not limited to specific victims but extend to anyone who crosses his path.

Foreshadowing: Earlier, Kyung-chul's attack on the schoolgirl already established his pattern of targeting random victims.

• KYUNG-CHUL
• taxi passengers
• killings
• murder rampage
• innocent victims