Ty is worried about Sully's dating Maggie; Faith and Bosco lose a witness who turns out to be the perp in a homicide; Bobby prepares for Matty's release from prison; while driving the bus, Carlos collides with a pregnant driver and later attempts to revive the baby she delivered prematurely after Sarah pronounces it dead, unaware of the consequences for the parents; Jimmy rescues a boy from a tree; Bosco and Ty take issue with Sully over his handling of a belligerent collar.

Yokas continues to have marital difficulties with Fred and, when she meets up with an old flame at the scene of a car accident, she finds herself very tempted to accept his invitation to meet him in his hotel room to catch up on old times. Doc's dad ends up in intensive care leaving Doc with some hard decisions. A perp accuses 'Candyman' of stealing money from him when he arrested him. Davis believes the criminal and is not sure how he is going to answer IAB's questions about what happened, even though he didn't see anything happen. The police station takes on the fire station in a basketball game.

Jimmy's recovery complicates his return to the firehouse as he tries to take on too much, causing discord amongst his fellow firefighters over his all-consuming need to prove his abilities have not been lost. Meanwhile, Alex Taylor joins the firehouse and arrives with some baggage of her own.

A disturbing visit from his former high school girlfriend forces Doc to confront a horrible act he has hidden for years; Carlos struggles to pass a medical school qualification exam.

Tatiana is still missing, and Sully continues to search for her while grieving her loss. When he comes upon the body of a six-year-old girl in a box on a curb, he becomes strangely unnerved. Haunted by this sight and by thoughts of the mistakes he has made recently, Sully takes the rest of the day off sick and winds up in a local restaurant where he finds his parish priest. They ruminate on the nature of guilt, absolution, forgiveness, faith, and the intercession of God as they recall the fate of another man who also made mistakes and tried to fix them, and whose life ended tragically at Sully's hand. Sully finally comes to a place where he can forgive himself and go on with life. He seeks out Davis to once again beg his forgiveness and reaffirm their connection to each other.

Hopelessly in love with Kylie and concerned that she will lose her Filipina heritage if she is adopted by a white couple, Carlos considers raising her until he realizes that the couple can give her the sister, the grandparents, and the extended family that he cannot. Kim's preoccupation with her new PDA drives Alex crazy until they are able to use it to save a very sick man, thus redeeming themselves in the eyes of a hypercritical Dr. Peterson. Faith and Fred are still on uneven ground about the Sergeant's exam. In an effort to shake Chevchenko's tree, Faith and Sully execute a clever plan to disrupt the Russian's bookmaking operation which also opens the door to the possibility of the still-missing Tatiana's return. Bosco is cleared for duty, and he and Faith agree to be partners again as soon as he returns.