Tony B is supposed to be dead, but his funeral leads Nash back to an old nemesis and blast from his past. Nick gets arrested for protesting the impending demolition of a building. Cassie goes on the hunt to find why this building is so important to Nick and how it ties into his past. Joe is accused by Inger of using marijuana, and Ulla is to blame. We find out about Nash's grandmother.
Nash and company track down a serial killer who picks people up in a cab; Rachel reveals the truth about what she's been up to at the SIU; and Cassidy debates whether she wants to be a cop anymore. Though not officially advertised at the time of airing, this was the series finale.