Stone and Angie go undercover to investigate a murder believed to be linked to a pornographic film industry. MeanWhile MacKenzie receives compromising photographs related to her past relationship with Chruch.
MacKenzie pushes Angie and Stone to solve the ongoing porn murder case, as the compromising photographs of herself and Church threaten the security of the Unit.
Rocca finds himself in unfamiliar territory when he goes undercover with Church on a case involving gold smuggling, political intrigue, and attempted assassination.
Working closely with a psychological profiler, Mackenzie puts her life on the line to trap a serial killer who uses the internet to select his victims.
A routine drug bust takes a sudden turn forcing Rocca to take the place of the target. Meanwhile, Church faces the challenge of a lifetime as he deals with a pregnant informant.
While the future of the undercover operation is under threat, Church has several meetings with his informant, Dingo. Finally, he extracts details with will enable the Singers group to bust a big-time drug ring.