When Det. Mac Taylor (Gary Sinise) arrives at the latest murder scene, Det. Flack (Eddie Cahill) tells him a man is dead. In a nod to the holidays, the warehouse has a Macy's Thanksgiving Day parade clown float in storage. Dr. Sheldon Hawkes (Hill Harper) comes to help, and Mac says he thought Hawkes might want to do an autopsy for 'old time's sake'. Hawkes used to be the medical examiner, but so far, he has yet to work on a balloon.
Det. Stella Bonasera (Melina Kankaredes) and Det. Danny Messer (Carmine Giovinazzo) process the scene while Flack questions apartment dwellers nearby. In a twisted turn, another man was in the alley having a paintball 'war' with the victim. The other man seems to have vanished. However, some paint is found on a pile of leaves, so the team takes a sample with them.
Back at the lab, Dr. Sid Hammerback (Robert Joy) tells Mac death was caused by gunshot to the chest. Another gunshot wound in the shoulder has black powder in it. Hawkes is taking a look at the bullet shell casing, and there were possibly three types of guns used.
The 'powder' turns out to be black cocaine, undetectable to police dogs. Mac tells Det. Lindsay Monroe (Anna Belknap) to cross-check the narcotics database. A major break soon comes. A DEA bust went down months ago, and the same 'black powder' was supposedly incinerated. The lead detective was Flack.
The resulting conversation is a tense one. When Mac explains, Flack realizes a cop might be 'dirty'. Since cops from the raid could be involved, Mac really needs Flack's notebook. Mac says somebody has to look, and he is asking as a friend. Flack asks if he has thought about consequences — Mac says consequences he cares about are the cops who didn't cross the line.
Mac finally reads Flack's notebook, and discovers which of the men is a murderous cop. The death was from a drug deal gone wrong. Mac confiscates badge and gun, then arrests him. As they walk to Central Booking, Flack is still wrestling with the idea of corruption.
Stella and Mac find the teenager following Stella. He is looking for his birth mother, but she was killed on 9/11. The woman married Mac, but planned to look for her son when he turned 18. Mac takes him to a restaurant and tells him the truth. He says the kid looks a lot like his mother. This could be a continuing storyline, so keep watching.
This episode opened the door into the lives of its characters. In only two conversations, the conflict over whether or not to let a "dirty" cop stay on the job is evident. Flack knows corruption can happen to anyone after his mentor compromised a case a couple of years ago and was fired. Now Flack is finding out what it feels like when someone under his command ignores ethics. It was bad enough when someone in high command was arrested for murder in "The Dove Commission". There was a distinct feeling about the internal struggles cops face every day when catching criminals. I also thought it was a smart move on Mac's part to bring Hawkes in on a case after having to remove him from the last one.