It's Baltimore, 1999. Hae Min Lee, a popular high-school senior, disappears after school one day. Six weeks later detectives arrest her classmate and ex-boyfriend, Adnan Syed, for her murder. He says he's innocent - though he can't exactly remember what he was doing on that January afternoon. But someone can. A classmate at Woodlawn High School says she knows where Adnan was. The trouble is, she’s nowhere to be found.