Family and friends of Adnan Syed, who is currently serving a life sentence for the murder of his ex-girlfriend 18-year-old Hae Min Lee, recall the events that led to Syed's arrest. After the podcast "Serial" resurrects the cold case, Syed's family prepares for his appeal in February 2016, and hope for a chance to discover the truth after nearly 20 years.

As Syed's appeal for a new trial gets underway, supporters look back at the 1999 confession of his friend, Jay Wilds, who claimed he helped Syed bury Lee's body. With questions remaining regarding the police's timeline of events, acquaintance Asia McClain becomes a key figure in providing a possible alibi for him.

Despite being granted a new trial, Adnan Syed and his attorneys contend with the State's repeated appeals. Private investigators grapple with outstanding questions as they re-analyze the forensic evidence surrounding Hae Min Lee's death and Syed faces a major decision as his 20th year in prison approaches. Series finale.