When a federal whistleblower is murdered while in FBI custody along with two agents, the team is stunned to find a familiar perpetrator has resurfaced. Meanwhile, OA wrestles with telling the team what is happening in his personal life.

After Maggie's sister, Erin, goes missing, the team begins an all-out search to recover her. But when Maggie discovers Erin was kidnapped by a sinister figure from her past, she must race to save her before it's too late.