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.

Emily discovers just what Faith's job entails and how much her mother loves her when they are taken hostage during a bank robbery, and Faith risks her life to save her daughter.

Over her protests, a judge marked for execution is placed under a protective detail and gives Sully and Ty a scare when she slips away to get a cup of coffee; Levine uses an unorthodox way to get a patient's mind off his pain; when no physical reason can be found for Faith's intense pain, her doctor refers her to a psychiatrist; Kim is livid when Doc gives her an official letter of reprimand for disregarding field regulations just the way he did several times; in an effort to get out of the bag and off the street, Maritza convinces Swersky to let her set up a sting operation to catch a chiropractor who's fronting for prostitution, and pays a terrible price for continuing her ""lonesome cowboy"" approach to apprehending criminals.

After a suspect in a jewelry store robbery starts displaying symptoms of a disease similar to SARS, the NIH is called in to figure out what is causing this, and hopefully stop this epidemic. Meanwhile, Cruz faces off with a gangbanger, who may have hired a 13 year old boy to carry out a murder.

The crossover continues on Medical Investigation S01E17 Half Life (II)