On Earth, a red line above your head reveals everyone you’ve slept with.

In a world where privacy no longer exists, a mysterious phenomenon causes a glowing red line to appear above people’s heads, connecting them to everyone they’ve ever slept with.
As relationships crumble and secrets are exposed, society spirals into chaos. Friends turn into enemies, lovers into strangers, and one determined journalist risks everything to uncover the truth behind the phenomenon before it destroys humanity.

A tense blend of drama, mystery, and social commentary, S-Line (2025) asks: What if your past could follow you everywhere — for everyone to see?