Tonight begins with the pairing of the newly promoted Det. Stone and Det. Sanchez.
They are investigating a drive-by shooting when Stone recognizes the victim as Calvin Gibbs, a local hero who is an all-conference tailback.
Det. Fitch goes to visit his wounded partner Washington at the hospital while Sgt. Longford and Det. Mahajan get the call to investigate a body discovered floating by a fisherman.

Hero

Det. Fitch shows up at the drive-by crime scene, sent by Lt. Mason to help out.  He finds Calvin’s cell phone by calling the number and finding a boy in the crows who had picked it up.  The detectives also figure out that there was a passenger in the car, and begin the hunt.  They track the last two calls made on Calvin’s phone to Shauna and Speedy.
Fitch tracks Shauna down at the local High School, where she tells him she talked to Calvin the night before.  Next the team goes after Speedy, who runs and is brought down by Stone.  During his interrogation, they learn he was the passenger, but Fitch rules him out as the shooter by tossing him a can of pop.  He catches it left-handed, which means he could not have shot Calvin from the passenger seat.
Their next potential suspect is Terence, Calvin’s older brother.  He has some priors and ran with a gang in the past.  They arrest him at work and bring him in for questioning.  Terence’s alibi checks out, and from him they learn that he had been trying to keep Calvin away from a club run by a man called the Goat.
They head to the Goat’s club, and learn that Goat had wanted Calvin to go into business with him.  Calvin refused, and Goat told him to leave.  After they leave there is a call for shots fired at the club.  They return to find Goat dying and several witnesses who ID Terence as the shooter.  Stone and Sanchez track Terence to the High School and arrest him for murder.
Meanwhile, Fitch runs with a clue has finds in a college football magazine.  An article showing Calvin’s tattoos points out the name “LaLa” on his chest and asks the question “Who is laLa”?  Fitch has seen the name before on Shauna’s necklace.  He goes to her house, and discovered that Calvin had seen her the night before, and her new boyfriend Derek had found it.  He took off after Calvin, and is the real shooter.  Fitch arrests him and brings him in.

Overboard

Longford and Mahajan see a party on a boat moored near where the body was found, and go to investigate.  They find out that the party is a wedding reception, and the body is the new groom.  The bride tells then her husband Stan went out for air and never came back.  She also tells them what a wonderful man Stan was and how everyone loved him.
After reviewing video and pictures of the party, they come up with a list of 15 suspects.  They bring them all in, and through questioning find out that every one of them hated Stan.  They discover from the autopsy that it was likely Stan had sex before he died.  This leads them to look at female suspects.  After reviewing more video, their main suspect is Lynette, one of the bridesmaids.  They bring her in for questioning, and she admits to having an affair with Stan.  She says when she left him, he was gray and asked her to get him a glass of water.  When she came back, he was gone.  The Medical Examiner then brings them the last piece of evidence – Stan died from multiple heart attacks, possible brought on by the stress of having sex.  He toppled over the rail, hitting his head and falling into the water.  Case closed.

Final Act
Fitch returns to the hospital, bringing a bottle of wine to see Washington and see his wife and new baby, Martin.  He tells Washington that there is a job waiting for him if he wants to come back.
After he leaves, they see Fitch speaking at a press conference about the shooting.  He tells the assembled reporters that his partner was the true hero that day.

FIN