Jimmy and Kim, still locked in a custody battle over Joey, meet with a court-appointed evaluator and plead their cases in a heated exchange.

When Sully and Tatiana visit his mother at her nursing home, Tatiana expresses concern over the quality and cost of his mother's care. Convinced that she can do a better job of taking care of her at home, she signs her out and moves her in with them. Sully is shocked and displeased, and tells Tatiana that it will be too difficult for her to take care of his mother.

Alex tries to stay busy to avoid dealing with her feelings about her father's death. Eager to fill empty hours and maintain the brave front her father insisted upon when she was growing up, she works extra shifts and even helps Carlos and Ty move into their new apartment. While Carlos is downstairs unloading the truck, Alex takes Ty up on his previous offer to talk and asks him about his father, who also died in the line of duty.

Doc visits Ryan, who's now walking during his physical therapy sessions.

Carlos decides to take a ride on the fire pole and falls, losing consciousness. Doc, Kim and Alex bring him to the ER where he is finally awake and combative. Dr. Thomas admits him to the hospital for observation because of his head lac and LOC. The nursing staff settles a score with Carlos by putting him in a room with Rodger, a drunk he brought in the day before. Rodger is alternating between screaming, crying, whimpering and non-stop talking -- all at the top of his lungs. He's going through the DTs and can't be sedated, because he admits to being drunk since 1987.

The news that Faith is repartnering with Bosco outrages Fred; Bosco overcomes his initial wariness about his brother's claims of sobriety after the tip Mikey gives him about Ecstasy dealers leads to a solid bust; in the wake of the hostage situation, the department shrink sent to debrief the house elicits a range of emotional reactions from Kim, Carlos and Holly as she reveals that Doc is in the Bellevue psych ward on a suicide watch, and that the toll of 9/11 and its aftermath may be at the root of his collapse; when she investigates the murder of an Ecstasy dealer outside a rave, Maritza discovers that the motive may be a turf war between rival dealers; Bosco is distraught when Maritza informs him that the evidence points to Mikey's being a major Ecstasy dealer who used him to eliminate the competition by providing the tip that lead to the raid; Bosco and Maritza set out separately to find Mikey; tragedy occurs when Maritza and Dade pull over Mikey's car outside a rave.

Maritza goes all out on the hunt for Michael after Dade dies, as does Bosco, who's intent on finding his brother before Maritza does; Faith calls Maritza a liar in front of Swersky when Maritza claims that she saw Michael shoot Dade; Fred is still angry about Faith repartnering with Bosco, and refuses to discuss it; Breene revisits the house and urges the paramedics to talk to professionals or to each other to help deal with the stress of the shootout; looking to collect the reward for information leading to Dade's killer, Anthony tells Maritza where Michael can be found after she lies to him about her relationship with Bosco; Bosco finds Michael moments before Maritza, and his brother claims that he's innocent and that a drug dealer named Spider was Dade's murderer; Spider comes out with machine guns blazing when Maritza, Sully, Ty, Faith and Bosco attempt to arrest him, and a ferocious gun battle ensues; Maritza agrees to work with Michael as an informant after Bosco pleads for his

Wary of Lester Martin, the high-priced lawyer his father has found for Mikey and the deal he's attempting to broker, Bosco warns his brother to stay away from Maritza, but Mikey decides to disregard his brother's advice and makes a deal to become her informant; for good measure, Bosco threatens to kill Maritza if anything happens to Mikey; Sully teases Ty about his budding relationship with Sasha; Faith and Bosco strike a deal with Laura, who also has no love lost for Maritza, to protect Mikey by helping her nab the drug dealers before Maritza gets to them; J.D. offers Kim a ride home, but stops off first at a rave that both Anti-Crime and Narcotics have staked out, thanks to information Mikey gave them; when some bad ecstasy begins to take a rapid toll, the paramedics call for backup, which prompts Maritza and her detail to storm the building; after an arsonist lobs a Molotov cocktail into the crowded building, Faith and Bosco give chase and capture him, while the firefighters rescue