Tunnel

March 25, 2017

Detective Park Gwang-ho (Choi Jin-hyuk) chases a serial killer through a tunnel in Hwaseong in 1986. He emerges in 2017. The disorientation, the technology, the changed world — all established in a single episode. The Hwaseong area grounds the drama's historical layer.

March 25, 2017

Gwang-ho's adjustment to 30 years of change — the specific details of a 1986 detective confronting the present.

April 1, 2017

The realisation that the serial killer Gwang-ho was chasing in 1986 is still active in 2017 — 30 years later.

April 1, 2017

Kim Seon-jae (Yoon Hyun-min), the 2017 detective Gwang-ho must work with, and his very different investigative style.

April 8, 2017

The connection between the drama's fictional killer and the real Hwaseong serial murders — the historical weight the drama carries.

April 8, 2017

The 2017 Seoul police's response to a detective who claims to be from 1986.

April 15, 2017

Gwang-ho's family — his wife and the daughter he left behind in 1986 — who have lived without him for 30 years.

April 15, 2017

The investigation at its midpoint — the killer's identity beginning to coalesce across 30 years of evidence.

April 22, 2017

The killer's psychological profile — how 30 years of getting away with murder shapes a person.

April 22, 2017

Kim Seon-jae's personal connection to the Hwaseong murders — the drama's most affecting revelation.

April 29, 2017

Evidence from 1986 and 2017 combined — the case that spans both times.

April 29, 2017

The killer's identity revealed to the audience if not yet to the characters.

May 6, 2017

Gwang-ho's choice between catching the killer and finding the tunnel back to 1986.

May 6, 2017

The 2017 version of the 1986 chase — the same detective, 30 years later, finally close.

May 13, 2017

The tunnel reappears. What Gwang-ho chooses.

May 13, 2017

The finale. One of OCN's finest dramas — a time-travel detective thriller that used the Hwaseong murders' historical weight with unusual care and intelligence.