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.

Their relationship began like a storybook high-school romance: a prom date, love notes, sneaking off to be alone. But unlike other kids at school, they had to keep their dating secret, because their parents disapproved. Both of them, but especially Adnan, were under special pressure at home, and the stress of that spilled over into their relationship. Eventually Hae broke up with Adnan. And then, depending on who you ask, Adnan was either understandably sad and moping around, or full of rage and plotting to kill her.

It’s February 9, 1999. Hae has been missing for three weeks. A man on his lunch break pulls off a road to pee, and stumbles on her body in a city forest. His odd recounting of the discovery makes Detectives Ritz and MacGillivary suspicious. For instance, why did he walk so far into the woods - 127 feet - to relieve himself? And that’s just the start. A look into the man’s past reveals some bizarre behavior.