Yokas clashes with her mother over her recovery; Maritza is back on the job, but unhappy that she's back in the bag and handing out parking tickets; Ty and Sully discover a truck carrying sick illegal aliens and end up scouring the city to track down one of them who escapes after it's determined that the aliens have a highly contagious and potentially fatal disease.

Sasha, Bosco, Sully and Ty get on the case of a malicious rapper. Ty considers returning to law school with the help of Sully. Jimmy struggles with his new position and his relationship with his co-workers when he makes a big mistake during a fire drill. Faith gets a physical therapist.

Sully kills one of the perps and shoots the denotator out of the hand of Frank Morgan, the bomber; Doc goes ballistic when he comes upon the scene of an accident involving his old rig and a city bus, and physically assaults Eugene; Public Morals raids Dr. Chow's office, and Maritza is forced to reveal her rape to keep Thomas Warner from being released on a D.A.T.; Ty gets Frank Morgan to flip on Gary Barnes, and Barbara promises Morgan that she will make sure he gets the death penalty for killing her housekeeper and driver; Kim and Carlos refuse to back up Eugene after he files a complaint against Doc, prompting Eugene to quit; a distraught Faith, still plagued by flashbacks of the shooting, asks Fred if they can get out of the city for a family vacation; Warner confesses to raping Maritza while Bosco is transporting him to the Tombs; Carlos is horrified when Doc admits that he accosted Eugene at his house because he ""killed Taylor""; Bosco turns Warner over to Maritza, who gets her pay

Sasha anonymously slips Ty the I.A.B. file on the cover up of his father's death; Faith visits Bosco and lets him know how much she misses having him for a partner; Sully bristles at being partnered with Brendan; Faith learns a hard lesson about good detective work when she lets herself get hoodwinked into acting on prejudice and ill-informed assumptions in arresting an innocent man for the death of a pregnant Muslim teenager; Brendan and Grace decide to start over and take their relationship along slowly; after Ty reaches out to exactly the wrong person in the department's top brass to uncover the truth behind his father's death, Finney sets the stage for letting Ty know about Sasha's I.A.B. assignment and threatens them both if they continue with their investigations; Fred gets custody of Charlie and Emily agrees to live with Faith; Sully pursues his options on coming forward about Ty Sr.'s death; Brendan once again single-handedly rushes to the rescue to prevent a suicide.

Ty rats out Sasha to the squad after Finney refuses to transfer her out; an action star doing research for his next movie goes on a ride along with the firefighters, and Stu quickly discovers that his boyhood hero is a failing alcoholic looking for a chance to revive a dead career; Brendan offers to ride with Sasha when everyone else refuses to do so, which leaves Ty and Sully partnered again; the retired detective who gave Sasha the real I.A.B. file on the death of Ty's father is found murdered by a police-issued bullet; Sully decides to testify against Finney; in pursuit of a drug dealer who shot an eight year old girl, Sasha and Brendan are injured, but the other units in the sector fail to respond to their calls for help until Ty and Sully finally relent and come to their aid.

In order to get enough evidence to convict C.T. Finney for the death of Ty Davis, Sr., Sully must look for the other officers involved with the incident, and also relive the events leading up to the murder.