Errand service owner Wu Hyeondo never expected his first love to walk back into his life, especially not like this. Seong Su arrives clutching a flyer for a suspicious cult, claiming his dead son might still be alive. Reeling from the sudden mention of a child he never knew about, Hyeondo assumes Seong Su must have moved on and built a family after he left the island. But the truth is far more shocking than he could have realized...