When Mac (Gary Sinise) hears about a man's murder, the solution is a relatively simple one. The victim has a wife. She confesses to killing him, so the case should be over and done with. If only things were that simple. Stella (Melina Kanakaredes) has the unfortunate task of giving Mac the bad news: it doesn't match their prime suspect. While the DNA is female in origin, it comes from someone else entirely.
Flack (Eddie Cahill) must now grill the confessor since she appears to be protecting another. Without perhaps meaning to, he mentions feeling okay about a wrongdoing does not take away any guilt. Wow! For the first time, Flack himself acknowledges what has more or less been an open secret. After his girlfriend Jessica was killed during a routine police job, a hunt for the killers had top priority ("Pay Up").
Flack killed a man, sort of. I have some reservations about the act being cold blooded out of pure revenge. Sometimes, a cop has to shoot first before a no-goodnik gains the upper hand. Eddie Cahill takes on the role of the tortured soul with solid raw skill. Flack is a character who is living with sorrow and trying desperately to hang on. Mac and a few others have noticed the troubling change, but no official action yet. It may only be a matter of time before a life is put in jeopardy.
Danny (Carmine Giovinazzo) is having problems of his own. A drive-by shooting paralyzed him from the waist down ("Pay Up"). He finally is standing on his feet. Now, does this mean he is able to walk? Perhaps. Then again, if he can pull himself to a standing position, bending over to pick up his daughter makes logical sense.
Sinclair (Mykelti Williamson) returns, since the current kerfluffle means pressure from the mayor's office to solve the case. Quickly. Sinise and Williamson work well as two who take their jobs seriously. Good thing, because Mac finds out the true cause of why there are more than a few deaths connected to the same person. Here's a hint – someone is sloppy. The key is not assuming anything without evidence to back up the theory.
Halen (Sarah Carter) appears to have settled in, and there is a reason why she works so hard. The double set of wages from her grant and crime cleanup duties help to pay off student loans.