Get ready for a chilling new dark fantasy thriller in a new Kdrama based on the red string of fate. A mysterious new poster and teaser have just been released for S Line (에스라인), starring Lee Soo Hyuk, Lee Da Hee, and Arin. The poster promises a strange world entangled in crimson threads.
In an interview with Deadline, Director Ahn said, “It’s a totally original concept based on the webtoon where red lines show how people are connected. The main theme that audiences should take away is how human society could collapse when the boundaries are stepped on.”
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The 6-episode thriller is an adaptation of the popular webtoon by Ggomabi, known for Netflix’s “A Killer Paradox.” Filmmaker Ahn Joo-Young (A Boy and Sungreen) takes on both directing and screenwriting duties, co-writing the script with Hwang Ho-Gil and Kim Joon-Hyun. The series was also selected for competition at the 2025 Canneseries (Cannes International Series Festival, Season 8), where its first two episodes had their world premiere.
What is S Line?
The series introduces a unique premise: since birth, Shin Hyun-Heub (Arin) has seen invisible red lines, or “S Lines,” connecting individuals who are or have been sexual partners. The newly released teaser offers a glimpse into her red-tinged vision as Hyun Heub gathers clues, questioning if others can see these lines and is determined to uncover their origin.
Adding to the baffling mystery, high school teacher Kyu-Jin (Lee Da Hee) begins distributing special glasses that allow wearers to see these same S Lines. When these glasses reach Detective Han Ji-Wook (Lee Soo Hyuk), scandalous and disturbing secrets are revealed. The teaser culminates in mounting chaos, with Kyu Jin eerily proclaiming that the world will soon be “bathed in red.”
First Look Images
S Line Cast
- Lee Soo-Hyuk as Han Ji-Wook
- Lee Da-Hee as Kyu-Jin
- Arin as Shin Hyun-Heub
- Lee Eun-Saem
- Nam Kyu-Hee
The festival’s non-competitive “Korean Fiction” segment will also showcase other works, including MBC’s “Doubt” (starring Han Seok Kyu, Chae Won Bin, Han Ye Ri) and U+ Mobile TV’s “Hunter with a Scalpel” (starring Park Yong Woo, Park Joo Hyun, Kang Hoon).
Watch The Teaser Trailer
