Sam weasels her way into an undercover play as a koi aficionado while Kelly forges a crucial new gang connection.

After learning that the entire purple rain operation has been compromised, Sam and Kelly drown their frustrations in work, discovering the best way to solve the case is to go back to the beginning.

Sam and Kelly set up an elaborate fake informant operation to uncover incriminating evidence in the purple rain case but the play is derailed when Naz becomes the prime suspect in a murder.

The OCE team works together to exonerate Naz and stop purple rain. Kelly and Nathan go undercover, Sam talks to an old friend, and Naz scrambles to remember a detail that can help arrest a killer. Series finale.