The Tooth and the Nail

Lee Seok-jin, a nationally famous circus magician, saves Jung Ha-yeon and the two form a close bond that grows into love. They become stage partners, performing together and eventually marry, with Ha-yeon becoming pregnant. Their life blends showmanship with a private happiness that belies the dangers looming from Ha-yeon's past.

On a bus, Seok-jin spots Ha-yeon passing a letter to a woman and confronts her about it. She explains that she was helping a passer-by, and the moment hints at a shadowy past. This foreshadows the danger and secrets surrounding Ha-yeon's copper-plate legacy.

After securing a new contract in Seoul, Seok-jin and Ha-yeon perform together and move into a hotel while on tour. Ha-yeon opens a bag in their hotel room and reveals a copper plate used to make counterfeit notes, explaining its origin from the Japanese era. The uncle who helped make it was killed, linking Ha-yeon's past to a deadly history.

Japanese police and Okamoto relentlessly press Ha-yeon for the location of the copper plate, forcing her to hide it and flee. The episode shows the peril that Ha-yeon's family faced long ago during the occupation. The copper plate's existence ties multiple characters to a deadly conspiracy.

Seok-jin's attempt to warn Okamoto comes too late as Ha-yeon is pushed to her death by an unseen hand. The loss devastates him and confirms the deadly reach of Ha-yeon's past. He mourns Ha-yeon and their unborn child, turning to grief that reshapes his life.

Grief drives Seok-jin into alcoholism and he abandons his circus career. He wanders the streets, mired in despair, until a chance encounter with a counterfeit note rekindles his drive for vengeance. The seeds of revenge begin to take root.

While intoxicated, Seok-jin discovers a counterfeit bank note on the street, confirming that the crime network Ha-yeon was entangled with remains active. This discovery sharpens his resolve to expose Okamoto and the others. He commits to a path of revenge rather than despair.

Following guidance from a Japanese officer, Seok-jin changes his appearance and adopts the alias Choi Seung-man to lure and locate Okamoto in Seoul. He then becomes Nam Do-jin's personal driver, observing him while the man is often accompanied by a mysterious woman. His multilingual clues hint at Okamoto's real identity and begin to connect the dots of the past.

Seok-jin spends his days as Do-jin's driver, living in the stone mansion and watching the man’s every move. He gradually tests whether Do-jin is the one behind the fake notes and Ha-yeon's murder, building his revenge plan from within. The tension between master and driver deepens as Do-jin's secrets begin to surface.

Do-jin engineers a phone call at 10 PM to the printer who knows about the copper plate, only for the printer to be killed by Do-jin when the truth surfaces. Mdm Sung overhears and taunts Seok-jin, insinuating that Ha-yeon was connected to Do-jin. The seeds of suspicion are sown as the chain of murders expands.

Do-jin murders Mdm Sung and dismembers her, claiming he killed Ha-yeon to silence her and that he never loved Sung or Ha-yeon. Seok-jin returns home with Sung's severed head, intensifying the cat-and-mouse game between them and bringing the case to a boiling point.

Seok-jin reveals in court that he was the anonymous caller who reported the murder, and Do-jin identifies him as Seung-man; tension erupts as Do-jin's attempt to attack is thwarted by guards. The prosecutor's case collapses without new evidence, and the judge warns of an acquittal unless fresh proof emerges.

In a dramatic climax, Do-jin ultimately confesses to killing Seung-man and is sentenced to life imprisonment for murder, with other charges to be addressed later. Seok-jin returns to the circus, resumes performing, and keeps Ha-yeon's memory alive with a photo of her and her ring by his side.